Methods for treating Huntington&#39;s Disease

ABSTRACT

The present description relates to a method or use of a compound for treating or ameliorating HD (Huntington&#39;s Disease) in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I):or a form thereof, wherein w1, w2, w3, w4, w5, w6 and w7 are as defined herein. In particular, the present description relates to a method of use of a compound of Formula (I) or a form or composition thereof for treating or ameliorating HD in a subject in need thereof comprising, administering an effective amount of the compound or a form or composition thereof to the subject.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage filing under 35 U.S.C. § 371 of International Application No. PCT/US2018/039775, filed Jun. 27, 2018, which in turn claims priority to U.S. Provisional Application No. 62/525,812, filed Jun. 28, 2017, the entire contents of which are incorporated by reference herein.

The present description relates to compounds, forms, and pharmaceutical compositions thereof and methods of using such compounds, forms, or compositions thereof for treating or ameliorating Huntington's disease. In particular, the present description relates to substituted monocyclic heteroaryl compounds, forms and pharmaceutical compositions thereof and methods of using such compounds, forms, or compositions thereof for treating or ameliorating Huntington's disease.

BACKGROUND

Huntington's Disease (HD) is a progressive, autosomal dominant neurodegenerative disorder of the brain, having symptoms characterized by involuntary movements, cognitive impairment, and mental deterioration. Death, typically caused by pneumonia or coronary artery disease, usually occurs 13 to 15 years after the onset of symptoms. The prevalence of HD is between three and seven individuals per 100,000 in populations of western European descent. In North America, an estimated 30,000 people have HD, while an additional 200,000 people are at risk of inheriting the disease from an affected parent. The disease is caused by an expansion of uninterrupted trinucleotide CAG repeats in the “mutant” huntingtin (Htt) gene, leading to production of HTT (Htt protein) with an expanded poly-glutamine (polyQ) stretch, also known as a “CAG repeat” sequence. There are no current small molecule therapies targeting the underlying cause of the disease, leaving a high unmet need for medications that can be used for treating or ameliorating HD. Consequently, there remains a need to identify and provide a small molecule compound for use in treating or ameliorating HD.

All other documents referred to herein are incorporated by reference into the present application as though fully set forth herein.

SUMMARY

The present description relates to a method or use of a compound for treating or ameliorating HD (Huntington's Disease) in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I):

or a form thereof, wherein w₁, w₂, w₃, w₄, w₅, w₆ and w₇ are as defined herein. In particular, the present description relates to a method of use of a compound of Formula (I) or a form or composition thereof for treating or ameliorating HD in a subject in need thereof comprising, administering an effective amount of the compound or a form or composition thereof, to the subject.

DETAILED DESCRIPTION

The present description relates to a method or use of a compound for treating or ameliorating HD (Huntington's Disease) in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I):

or a form thereof, wherein:

-   w₁ and w₅ are independently C—R_(a) or N; -   w₂ is C—R_(b) or N; -   w₃, w₄ and w₇ are independently C—R₁, C—R₂, C—R_(a) or N; -   w₆ is C—R₁, C—R₂, C—R_(e) or N; -   wherein one of w₃, w₄, w₆ and w₇ is C—R₁ and one other of w₃, w₄, w₆     and w₇ is C—R₂, provided that, -   when w₃ is C—R₁, then w₆ is C—R₂ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₃ is C—R₂, then w₆ is C—R₁ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₄ is C—R₁, then w₇ is C—R₂ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N; or, -   when w₄ is C—R₂, then w₇ is C—R₁ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N; and, -   wherein any one, two or three of w₁, w₂, w₃, w₄, w₅, w₆ and w₇ may     optionally be N; -   R₁ is C₁₋₈alkyl, amino, C₁₋₈alkyl-amino, (C₁₋₈alkyl)₂-amino,     C₁₋₈alkoxy-C₁₋₈alkyl-amino, (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino, amino-C₁₋₈alkyl,     C₁₋₈alkyl-amino-C₁₋₈alkyl, (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     amino-C₁₋₈alkyl-amino, (amino-C₁₋₈alkyl)₂-amino,     (amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino, C₁₋₈alkyl-amino-C₁₋₈alkyl-amino,     (C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino,     (C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     [(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino, amino-C₁₋₈alkoxy,     C₁₋₈alkyl-amino-C₁₋₈alkoxy, (C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy,     C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy,     amino-C₂₋₈alkenyl, C₁₋₈alkyl-amino-C₂₋₈alkenyl,     (C₁₋₈alkyl)₂-amino-C₂₋₈alkenyl, amino-C₂₋₈alkynyl,     C₁₋₈alkyl-amino-C₂₋₈alkynyl, (C₁₋₈alkyl)₂-amino-C₂₋₈alkynyl,     halo-C₁₋₈alkyl-amino, (halo-C₁₋₈alkyl)₂-amino,     (halo-C₁₋₈alkyl)(C₁₋₈alkyl)amino, hydroxy-C₁₋₈alkyl,     hydroxy-C₁₋₈alkoxy-C₁₋₈alkyl, hydroxy-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl)₂-amino, (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl-amino,     [(hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino,     [(hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl](C₁₋₈alkyl)amino,     heterocyclyl, heterocyclyl-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkoxy,     heterocyclyl-amino, (heterocyclyl)(C₁₋₈alkyl)amino,     heterocyclyl-amino-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkyl-amino,     (heterocyclyl-C₁₋₈alkyl)₂-amino,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     heterocyclyl-oxy, heterocyclyl-carbonyl, heterocyclyl-carbonyl-oxy,     C₃₋₁₄cycloalkyl, aryl-C₁₋₈alkyl-amino, (aryl-C₁₋₈alkyl)₂-amino,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl, heteroaryl,     heteroaryl-C₁₋₈alkyl, heteroaryl-C₁₋₈alkoxy, heteroaryl-amino,     heteroaryl-C₁₋₈alkyl-amino, (heteroaryl-C₁₋₈alkyl)₂-amino,     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heteroaryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; -   wherein, each instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and     heteroaryl is optionally substituted with one, two or three R₃     substituents and optionally, with one additional R₄ substituent; or, -   wherein, each instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and     heteroaryl is optionally substituted with one, two, three or four R₃     substituents; -   R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl,     heteroaryl or heteroaryl-amino; wherein, each instance of aryl,     heterocyclyl and heteroaryl is optionally substituted with one, two     or three R₆ substituents and optionally, with one additional R₇     substituent; -   R_(a) is, in each instance, independently selected from hydrogen,     halogen or C₁₋₈alkyl; -   R_(b) is hydrogen, halogen, C₁₋₈alkyl or C₁₋₈alkoxy; -   R_(c) is hydrogen, halogen or C₁₋₈alkyl; -   R₃ is, in each instance, independently selected from cyano, halogen,     hydroxy, oxo, C₁₋₈alkyl, halo-C₁₋₈alkyl, C₁₋₈alkyl-carbonyl,     C₁₋₈alkoxy, halo-C₁₋₈alkoxy, C₁₋₈alkoxy-C₁₋₈alkyl,     C₁₋₈alkoxy-carbonyl, amino, C₁₋₈alkyl-amino, (C₁₋₈alkyl)₂-amino,     amino-C₁₋₈alkyl, C₁₋₈alkyl-amino-C₁₋₈alkyl,     (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl, amino-C₁₋₈alkyl-amino,     C₁₋₈alkyl-amino-C₁₋₈alkyl-amino, (C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino,     (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     [(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl]2-amino,     (C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     [(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino,     C₁₋₈alkoxy-C₁₋₈alkyl-amino, (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino, C₁₋₈alkyl-carbonyl-amino,     C₁₋₈alkoxy-carbonyl-amino, hydroxy-C₁₋₈alkyl,     hydroxy-C₁₋₈alkoxy-C₁₋₈alkyl, hydroxy-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl)₂-amino or (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino; -   R₄ is C₃₋₁₄cycloalkyl, C₃₋₁₄cycloalkyl-C₁₋₈alkyl,     C₃₋₁₄cycloalkyl-amino, aryl-C₁₋₈alkyl, aryl-C₁₋₈alkoxy-carbonyl,     aryl-sulfonyloxy-C₁₋₈alkyl, heterocyclyl or heterocyclyl-C₁₋₈alkyl;     wherein, each instance of C₃₋₁₄cycloalkyl, aryl and heterocyclyl is     optionally substituted with one, two or three R₅ substituents; -   R₅ is, in each instance, independently selected from halogen,     hydroxy, cyano, nitro, C₁₋₈alkyl, halo-C₁₋₈alkyl, C₁₋₈alkoxy,     halo-C₁₋₈alkoxy, amino, C₁₋₈alkyl-amino, (C₁₋₈alkyl)₂-amino or     C₁₋₈alkyl-thio; -   R₆ is, in each instance, independently selected from halogen,     hydroxy, cyano, nitro, C₁₋₈alkyl, C₂₋₈alkenyl, halo-C₁₋₈alkyl,     hydroxy-C₁₋₈alkyl, C₁₋₈alkoxy, halo-C₁₋₈alkoxy,     C₁₋₈alkoxy-C₁₋₈alkyl, amino, C₁₋₈alkyl-amino, (C₁₋₈alkyl)₂-amino or     C₁₋₈alkyl-thio; and, -   R₇ is C₃₋₁₄cycloalkyl, C₃₋₁₄cycloalkyl-oxy, aryl, heterocyclyl or     heteroaryl; and, wherein the form of the compound is selected from     the group consisting of a salt, prodrug, hydrate, solvate,     clathrate, isotopologue, racemate, enantiomer, diastereomer,     stereoisomer, polymorph and tautomer form thereof. -   In one aspect of the use of a compound of Formula (I), w₁ is     C—R_(a). -   In another aspect of the use of a compound of Formula (I), w₁ is N. -   In one aspect of the use of a compound of Formula (I), w₂ is     C—R_(b). -   In another aspect of the use of a compound of Formula (I), w₂ is N. -   In one aspect of the use of a compound of Formula (I), w₃ is     C—R_(a). -   In another aspect of the use of a compound of Formula (I), w₃ is N. -   In one aspect of the use of a compound of Formula (I), w₄ is     C—R_(a). -   In another aspect of the use of a compound of Formula (I), w₄ is N. -   In one aspect of the use of a compound of Formula (I), w₅ is     C—R_(a). -   In another aspect of the use of a compound of Formula (I), w₅ is N. -   In one aspect of the use of a compound of Formula (I), w₆ is     C—R_(e). -   In another aspect of the use of a compound of Formula (I), w₆ is N. -   In one aspect of the use of a compound of Formula (I), w₇ is     C—R_(a). -   In another aspect of the use of a compound of Formula (I), w₇ is N. -   In one aspect of the use of a compound of Formula (I), w₃ is C—R₁     and w₆ is C—R₂. -   In another aspect of the use of a compound of Formula (I), w₃ is     C—R₂ and w₆ is C—R₁. -   In one aspect of the use of a compound of Formula (I), w₄ is C—R₁     and w₇ is C—R₂. -   In another aspect of the use of a compound of Formula (I), w₄ is     C—R₂ and w₇ is C—R₁. -   In one aspect of the use of a compound of Formula (I), w₃ is C—R₁,     w₆ is C—R₂ and w₁, w₄, w₅ and w₇ are independently C—R_(a) or N and     w₂ is C—R_(b) or N. -   In another aspect of the use of a compound of Formula (I), w₃ is     C—R₂, w₆ is C—R₁ and w₁, w₄, w₅ and w₇ are independently C—R_(a) or     N and w₂ is C—R_(b) or N. -   In one aspect of the use of a compound of Formula (I), w₄ is C—R₁,     w₇ is C—R₂, w₁, w₃ and w₅ are independently C—R_(a) or N, w₂ is     C—R_(b) or N and w₆ is C—R_(e) or N. -   In another aspect of the use of a compound of Formula (I), w₄ is     C—R₂, w₇ is C—R₁, w₁, w₃ and w₅ are independently C—R_(a) or N, w₂     is C—R_(b) or N and w₆ is C—R_(e) or N. -   In one aspect of the use of a compound of Formula (I), w₁ and w₂ are     N. -   In one aspect of the use of a compound of Formula (I), w₁ and w₃ are     N. -   In one aspect of the use of a compound of Formula (I), w₁ and w₄ are     N. -   In one aspect of the use of a compound of Formula (I), w₁ and w₅ are     N. -   In one aspect of the use of a compound of Formula (I), w₁ and w₆ are     N. -   In one aspect of the use of a compound of Formula (I), w₁ and w₇ are     N. -   In one aspect of the use of a compound of Formula (I), -   R₁ is C₁₋₈alkyl, amino, C₁₋₈alkyl-amino, (C₁₋₈alkyl)₂-amino,     C₁₋₈alkoxy-C₁₋₈alkyl-amino, (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino, amino-C₁₋₈alkyl,     C₁₋₈alkyl-amino-C₁₋₈alkyl, (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     amino-C₁₋₈alkyl-amino, (amino-C₁₋₈alkyl)₂-amino,     (amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino, C₁₋₈alkyl-amino-C₁₋₈alkyl-amino,     (C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino,     (C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     [(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino, amino-C₁₋₈alkoxy,     C₁₋₈alkyl-amino-C₁₋₈alkoxy, (C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy,     (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy,     amino-C₂₋₈alkenyl, C₁₋₈alkyl-amino-C₂₋₈alkenyl,     (C₁₋₈alkyl)₂-amino-C₂₋₈alkenyl, amino-C₂₋₈alkynyl,     C₁₋₈alkyl-amino-C₂₋₈alkynyl, (C₁₋₈alkyl)₂-amino-C₂₋₈alkynyl,     halo-C₁₋₈alkyl-amino, (halo-C₁₋₈alkyl)₂-amino,     (halo-C₁₋₈alkyl)(C₁₋₈alkyl)amino, hydroxy-C₁₋₈alkyl,     hydroxy-C₁₋₈alkoxy-C₁₋₈alkyl, hydroxy-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl)₂-amino, (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl-amino,     [(hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino,     [(hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl](C₁₋₈alkyl)amino,     heterocyclyl, heterocyclyl-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkoxy,     heterocyclyl-amino, (heterocyclyl)(C₁₋₈alkyl)amino,     heterocyclyl-amino-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkyl-amino,     (heterocyclyl-C₁₋₈alkyl)₂-amino,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     heterocyclyl-oxy, heterocyclyl-carbonyl, heterocyclyl-carbonyl-oxy,     C₃₋₁₄cycloalkyl, aryl-C₁₋₈alkyl-amino, (aryl-C₁₋₈alkyl)₂-amino,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl, heteroaryl,     heteroaryl-C₁₋₈alkyl, heteroaryl-C₁₋₈alkoxy, heteroaryl-amino,     heteroaryl-C₁₋₈alkyl-amino, (heteroaryl-C₁₋₈alkyl)₂-amino,     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heteroaryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; wherein, each     instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and heteroaryl is     optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is amino, (C₁₋₈alkyl)₂-amino, C₁₋₈alkoxy-C₁₋₈alkyl-amino,     (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino, amino-C₁₋₈alkyl,     C₁₋₈alkyl-amino-C₁₋₈alkyl, (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     amino-C₁₋₈alkyl-amino, (amino-C₁₋₈alkyl)₂-amino,     (amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino, C₁₋₈alkyl-amino-C₁₋₈alkyl-amino,     (C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino,     (C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     [(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino, amino-C₁₋₈alkoxy,     C₁₋₈alkyl-amino-C₁₋₈alkoxy, (C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy,     (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy,     amino-C₂₋₈alkenyl, C₁₋₈alkyl-amino-C₂₋₈alkenyl,     (C₁₋₈alkyl)₂-amino-C₂₋₈alkenyl, amino-C₂₋₈alkynyl,     C₁₋₈alkyl-amino-C₂₋₈alkynyl, (C₁₋₈alkyl)₂-amino-C₂₋₈alkynyl,     halo-C₁₋₈alkyl-amino, (halo-C₁₋₈alkyl)₂-amino,     (halo-C₁₋₈alkyl)(C₁₋₈alkyl)amino, hydroxy-C₁₋₈alkyl,     hydroxy-C₁₋₈alkoxy-C₁₋₈alkyl, hydroxy-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl)₂-amino, (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl-amino,     [(hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino,     [(hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl](C₁₋₈alkyl)amino,     heterocyclyl, heterocyclyl-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkoxy,     heterocyclyl-amino, (heterocyclyl)(C₁₋₈alkyl)amino,     heterocyclyl-amino-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkyl-amino,     (heterocyclyl-C₁₋₈alkyl)₂-amino,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     heterocyclyl-oxy, heterocyclyl-carbonyl, heterocyclyl-carbonyl-oxy,     C₃₋₁₄cycloalkyl, aryl-C₁₋₈alkyl-amino, (aryl-C₁₋₈alkyl)₂-amino,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl, heteroaryl,     heteroaryl-C₁₋₈alkyl, heteroaryl-C₁₋₈alkoxy,     heteroaryl-C₁₋₈alkyl-amino, (heteroaryl-C₁₋₈alkyl)₂-amino,     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heteroaryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; wherein, each     instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and heteroaryl is     optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is C₁₋₈alkyl, amino, C₁₋₈alkyl-amino, (C₁₋₈alkyl)₂-amino,     C₁₋₈alkoxy-C₁₋₈alkyl-amino, (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino, amino-C₁₋₈alkyl,     C₁₋₈alkyl-amino-C₁₋₈alkyl, (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     amino-C₁₋₈alkyl-amino, (amino-C₁₋₈alkyl)₂-amino,     (amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino, C₁₋₈alkyl-amino-C₁₋₈alkyl-amino,     (C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino,     (C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     [(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino, amino-C₁₋₈alkoxy,     C₁₋₈alkyl-amino-C₁₋₈alkoxy, (C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy,     (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy,     amino-C₂₋₈alkenyl, C₁₋₈alkyl-amino-C₂₋₈alkenyl,     (C₁₋₈alkyl)₂-amino-C₂₋₈alkenyl, amino-C₂₋₈alkynyl,     C₁₋₈alkyl-amino-C₂₋₈alkynyl, (C₁₋₈alkyl)₂-amino-C₂₋₈alkynyl,     halo-C₁₋₈alkyl-amino, (halo-C₁₋₈alkyl)₂-amino,     (halo-C₁₋₈alkyl)(C₁₋₈alkyl)amino, hydroxy-C₁₋₈alkyl,     hydroxy-C₁₋₈alkoxy-C₁₋₈alkyl, hydroxy-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl)₂-amino, (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl-amino,     [(hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino or     [(hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl](C₁₋₈alkyl)amino. -   In another aspect of the use of a compound of Formula (I), -   R₁ is heterocyclyl, heterocyclyl-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkoxy,     heterocyclyl-amino, (heterocyclyl)(C₁₋₈alkyl)amino,     heterocyclyl-amino-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkyl-amino,     (heterocyclyl-C₁₋₈alkyl)₂-amino,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     heterocyclyl-oxy, heterocyclyl-carbonyl, heterocyclyl-carbonyl-oxy,     C₃₋₁₄cycloalkyl, aryl-C₁₋₈alkyl-amino, (aryl-C₁₋₈alkyl)₂-amino,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl, heteroaryl,     heteroaryl-C₁₋₈alkyl, heteroaryl-C₁₋₈alkoxy, heteroaryl-amino,     heteroaryl-C₁₋₈alkyl-amino, (heteroaryl-C₁₋₈alkyl)₂-amino,     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heteroaryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; wherein, each     instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and heteroaryl is     optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is heterocyclyl, heterocyclyl-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkoxy,     heterocyclyl-amino, (heterocyclyl)(C₁₋₈alkyl)amino,     heterocyclyl-amino-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkyl-amino,     (heterocyclyl-C₁₋₈alkyl)₂-amino,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     heterocyclyl-oxy, heterocyclyl-carbonyl or     heterocyclyl-carbonyl-oxy; wherein, each instance of heterocyclyl is     optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl optionally substituted with one, two or three R₃     substituents and optionally, with one additional R₄ substituents;     or, optionally, with one, two, three or four R₃ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     C₃₋₁₄cycloalkyl optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is aryl-C₁₋₈alkyl-amino, (aryl-C₁₋₈alkyl)₂-amino,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; wherein, each instance     of aryl is optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     aryl-C₁₋₈alkyl-amino optionally substituted with R₃ and R₄     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is heteroaryl, heteroaryl-C₁₋₈alkyl, heteroaryl-C₁₋₈alkoxy,     heteroaryl-amino, heteroaryl-C₁₋₈alkyl-amino,     (heteroaryl-C₁₋₈alkyl)₂-amino,     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heteroaryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; wherein, each     instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and heteroaryl is     optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heteroaryl optionally substituted with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), -   R₁ is heterocyclyl selected from azetidinyl, tetrahydrofuranyl,     pyrrolidinyl, piperidinyl, piperazinyl, 1,4-diazepanyl,     3,6-dihydropyridinyl, 1,2,5,6-tetrahydropyridinyl,     1,2,3,6-tetrahydropyridinyl, hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl,     (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl,     (3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl,     hexahydropyrrolo[3,4-b]pyrrol-(2H)-yl,     (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-(2H)-yl,     hexahydropyrrolo[3,4-c]pyrrol-(1H)-yl,     (3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-(1H)-yl,     1,3,3a,4,6,6a-hexahydropyrrolo[3,4-c]pyrrolyl,     octahydro-5H-pyrrolo[3,2-c]pyridinyl,     octahydro-6H-pyrrolo[3,4-b]pyridinyl,     (4aR,7aR)-octahydro-6H-pyrrolo[3,4-b]pyridinyl,     (4aS,7aS)-octahydro-6H-pyrrolo[3,4-b]pyridinyl,     hexahydropyrrolo[1,2-a]pyrazin-(2H)-one,     hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (7R,8aS)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aS)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aR)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aS)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazinyl,     (8aR)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazinyl,     (8aS)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazinyl,     (8aR)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazinyl,     (8aS)-octahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aR)-octahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     octahydro-2H-pyrido[1,2-a]pyrazinyl,     (3aR,4aR,7aS)-hexahydro-1H-cyclobuta[1,2-c:1,4-c′]dipyrrol-(3H)-yl,     3-azabicyclo[3.1.0]hexyl, (1R,5S)-3-azabicyclo[3.1.0]hexyl,     8-azabicyclo[3.2.1]octyl, (1R,5S)-8-azabicyclo[3.2.1]octyl,     8-azabicyclo[3.2.1]oct-2-enyl,     (1R,5S)-8-azabicyclo[3.2.1]oct-2-enyl, 9-azabicyclo[3.3.1]nonyl,     (1R,5S)-9-azabicyclo[3.3.1]nonyl, 2,5-diazabicyclo[2.2.1]heptyl,     (1S,4S)-2,5-diazabicyclo[2.2.1]heptyl, 2,5-diazabicyclo[2.2.2]octyl,     3,6-diazabicyclo[3.2.0]heptyl, 3,8-diazabicyclo[3.2.1]octyl,     (1R,5S)-3,8-diazabicyclo[3.2.1]octyl, 1,4-diazabicyclo[3.2.2]nonyl,     azaspiro[3.3]heptyl, 2,6-diazaspiro[3.3]heptyl,     4,7-diazaspiro[2.5]octyl, 2,6-diazaspiro[3.4]octyl,     2,7-diazaspiro[3.5]nonyl, 5,8-diazaspiro[3.5]nonyl,     2,7-diazaspiro[4.4]nonyl or 6,9-diazaspiro[4.5]decyl; wherein, each     instance of heterocyclyl is optionally substituted with one, two or     three R₃ substituents and optionally, with one additional R₄     substituent; or, optionally, with one, two, three or four R₃     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is heterocyclyl selected from azetidin-1-yl,     tetrahydrofuran-3-yl, pyrrolidin-1-yl, piperidin-1-yl,     piperidin-4-yl, piperazin-1-yl, 1,4-diazepan-1-yl,     3,6-dihydropyridin-4-yl, 1,2,5,6-tetrahydropyridin-5-yl,     1,2,3,6-tetrahydropyridin-4-yl,     hexahydropyrrolo[3,4-b]pyrrol-1(2H)-yl,     (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-1(2H)-yl,     (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl,     (3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-5 (1H)-yl,     hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl,     (3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl,     octahydro-5H-pyrrolo[3,2-c]pyridin-5-yl,     octahydro-6H-pyrrolo[3,4-b]pyridin-6-yl,     (4aR,7aR)-octahydro-6H-pyrrolo[3,4-b]pyridin-6-yl,     (4aS,7aS)-octahydro-6H-pyrrolo[3,4-b]pyridin-6-yl,     hexahydropyrrolo[1,2-a]pyrazin-6(2H)-one,     hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl,     (7R,8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl,     (8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl,     (8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl,     (8aS)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazin-2-yl,     (8aR)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazin-2-yl,     (8aS)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazin-2-yl,     (8aR)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazin-2-yl,     (8aS)-octahydropyrrolo[1,2-a]pyrazin-2(1H)-yl,     (8aR)-octahydropyrrolo[1,2-a]pyrazin-2(1H)-yl,     octahydro-2H-pyrido[1,2-a]pyrazin-2-yl,     (3aR,4aR,7aS)-hexahydro-1H-cyclobuta[1,2-c:1,4-c′]dipyrrol-2(3H)-yl,     3-azabicyclo[3.1.0]hex-3-yl, 8-azabicyclo[3.2.1]oct-3-yl,     (1R,5S)-8-azabicyclo[3.2.1]oct-3-yl,     8-azabicyclo[3.2.1]oct-2-en-3-yl,     (1R,5S)-8-azabicyclo[3.2.1]oct-2-en-3-yl,     9-azabicyclo[3.3.1]non-3-yl, (1R,5S)-9-azabicyclo[3.3.1]non-3-yl,     2,5-diazabicyclo[2.2.1]hept-2-yl,     (1S,4S)-2,5-diazabicyclo[2.2.1]hept-2-yl,     2,5-diazabicyclo[2.2.2]oct-2-yl, 3,6-diazabicyclo[3.2.0]hept-3-yl,     3,8-diazabicyclo[3.2.1]oct-3-yl,     (1R,5S)-3,8-diazabicyclo[3.2.1]oct-3-yl,     1,4-diazabicyclo[3.2.2]non-4-yl, azaspiro[3.3]hept-2-yl,     2,6-diazaspiro[3.3]hept-2-yl, 4,7-diazaspiro[2.5]oct-7-yl,     2,6-diazaspiro[3.4]oct-2-yl, 2,7-diazaspiro[3.5]non-2-yl,     2,7-diazaspiro[3.5]non-7-yl, 5,8-diazaspiro[3.5]non-8-yl,     2,7-diazaspiro[4.4]non-2-yl or 6,9-diazaspiro[4.5]dec-9-yl; wherein,     each instance of heterocyclyl is optionally substituted with one,     two or three R₃ substituents and optionally, with one additional R₄     substituent; or, optionally, with one, two, three or four R₃     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is substituted heterocyclyl selected from     (3R)-3-pyrrolidin-1-ylpyrrolidin-1-yl, 1-methylpiperidin-4-yl,     1-ethylpiperidin-4-yl, 2,2,6,6-tetramethylpiperidin-4-yl, (3     S)-3-methylpiperazin-1-yl, 4-methylpiperazin-1-yl,     4-ethylpiperazin-1-yl, 3-(trifluoromethyl)piperazin-1-yl,     1-tert-butoxy-carbonyl-3,6-dihydropyridin-4-yl,     1-ethyl-1,2,3,6-tetrahydropyridin-4-yl,     2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridin-4-yl,     4-methyl-1,4-diazepan-1-yl,     (3aS,6aS)-1-methylhexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl,     (3aS,6aS)-5-methylhexahydropyrrolo[3,4-b]pyrrol-1 (2H)-yl, (3 aR,     6aR)-1-methylhexahydropyrrolo[3,4-b]pyrrol-5 (1H)-yl,     (3aR,6aS)-5-methylhexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl,     (3aR,6aS)-5-(2-hydroxyethyl)hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl,     (3aR,6aS)-5-(propan-2-yl)hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl,     (3aR,6aS)-5-ethylhexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl,     (4aR,7aR)-1-methyloctahydro-6H-pyrrolo[3,4-b]pyridin-6-yl,     (4aR,7aR)-1-ethyloctahydro-6H-pyrrolo[3,4-b]pyridin-6-yl,     (4aR,7aR)-1-(2-hydroxyethyl)octahydro-6H-pyrrolo[3,4-b]pyridin-6-yl,     (4aS,7aS)-1-methyloctahydro-6H-pyrrolo[3,4-b]pyridin-6-yl,     (4aS,7aS)-1-(2-hydroxyethyl)octahydro-6H-pyrrolo[3,4-b]pyridin-6-yl,     (7R,8aS)-7-hydroxyhexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl,     (8aS)-8a-methyl-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazin-2-yl,     (8aR)-8a-methyl-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazin-2-yl,     (8aS)-8a-methyloctahydropyrrolo[1,2-a]pyrazin-2(1H)-yl,     (8aR)-8a-methyloctahydropyrrolo[1,2-a]pyrazin-2(1H)-yl,     (1R,5S,6s)-6-(dimethylamino)-3-azabicyclo[3.1.0]hex-3-yl,     (1R,5S)-8-methyl-8-azabicyclo[3.2.1]oct-3-yl,     9-methyl-9-azabicyclo[3.3.1]non-3-yl,     (3-exo)-9-methyl-9-azabicyclo[3.3.1]non-3-yl,     (1R,5S)-9-methyl-9-azabicyclo[3.3.1]non-3-yl,     (1S,4S)-5-methyl-2,5-diazabicyclo[2.2.1]hept-2-yl,     (1S,4S)-5-ethyl-2,5-diazabicyclo[2.2.1]hept-2-yl or     6-methyl-2,6-diazaspiro[3.3]hept-2-yl. -   In one aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-C₁₋₈alkyl, wherein heterocyclyl is selected from     morpholinyl, piperidinyl, piperazinyl, imidazolyl or pyrrolidinyl;     and, wherein, each instance of heterocyclyl is optionally     substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-C₁₋₈alkyl selected from morpholin-4-yl-methyl,     morpholin-4-yl-ethyl, morpholin-4-yl-propyl, piperidin-1-yl-methyl,     piperazin-1-yl-methyl, piperazin-1-yl-ethyl, piperazin-1-yl-propyl,     piperazin-1-yl-butyl, imidazol-1-yl-methyl, imidazol-1-yl-ethyl,     imidazol-1-yl-propyl, imidazol-1-yl-butyl, pyrrolidin-1-yl-methyl,     pyrrolidin-1-yl-ethyl, pyrrolidin-1-yl-propyl or     pyrrolidin-1-yl-butyl; wherein, each instance of heterocyclyl is     optionally substituted with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-C₁₋₈alkoxy, wherein heterocyclyl is selected from     pyrrolidinyl, piperidinyl or morpholinyl; and, wherein, each     instance of heterocyclyl is optionally substituted with R₃ and R₄     substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-C₁₋₈alkoxy selected from pyrrolidin-2-yl-methoxy,     pyrrolidin-2-yl-ethoxy, pyrrolidin-1-yl-methoxy,     pyrrolidin-1-yl-ethoxy, piperidin-1-yl-methoxy,     piperidin-1-yl-ethoxy, morpholin-4-yl-methoxy or     morpholin-4-yl-ethoxy; wherein, each instance of heterocyclyl is     optionally substituted with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-amino, wherein heterocyclyl is selected from     azetidinyl, pyrrolidinyl, piperidinyl, 9-azabicyclo[3.3.1]nonyl or     (1R,5S)-9-azabicyclo[3.3.1]nonyl; and, wherein, each instance of     heterocyclyl is optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-amino selected from azetidin-3-yl-amino,     pyrrolidin-3-yl-amino, piperidin-4-yl-amino,     9-azabicyclo[3.3.1]non-3-yl-amino,     (1R,5S)-9-azabicyclo[3.3.1]non-3-yl-amino,     9-methyl-9-azabicyclo[3.3.1]non-3-yl-amino,     (3-exo)-9-methyl-9-azabicyclo[3.3.1]non-3-yl-amino or     (1R,5S)-9-methyl-9-azabicyclo[3.3.1]non-3-yl-amino; wherein, each     instance of heterocyclyl is optionally substituted with R₃ and R₄     substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     (heterocyclyl)(C₁₋₈alkyl)amino, wherein heterocyclyl is selected     from pyrrolidinyl or piperidinyl; and, wherein, each instance of     heterocyclyl is optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     (heterocyclyl)(C₁₋₈alkyl)amino selected from     (pyrrolidin-3-yl)(methyl)amino or (piperidin-4-yl)(methyl)amino;     wherein, each instance of heterocyclyl is optionally substituted     with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-amino-C₁₋₈alkyl, wherein heterocyclyl is selected from     tetrahydrofuranyl; and, wherein, each instance of heterocyclyl is     optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-amino-C₁₋₈alkyl, selected from     3-(tetrahydrofuran-3-yl-amino)propyl; wherein, each instance of     heterocyclyl is optionally substituted with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl, wherein heterocyclyl is     selected from tetrahydrofuranyl, thienyl or pyridinyl; and, wherein,     each instance of heterocyclyl is optionally substituted with R₃ and     R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl, selected from     3-[(tetrahydrofuran-2-ylmethyl)amino]propyl,     3-[(thienyl-3-ylmethyl)amino]propyl,     3-[(pyridin-2-ylmethyl)amino]propyl or     3-[(pyridin-4-ylmethyl)amino]propyl; wherein, each instance of     heterocyclyl is optionally substituted with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-oxy, wherein heterocyclyl is selected from pyrrolidinyl     or piperidinyl; and, wherein, each instance of heterocyclyl is     optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-oxy selected from pyrrolidin-3-yl-oxy or     piperidin-4-yl-oxy; wherein, each instance of heterocyclyl is     optionally substituted with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-carbonyl, wherein heterocyclyl is selected from     piperazinyl; and, wherein, each instance of heterocyclyl is     optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-carbonyl selected from piperazin-1-yl-carbonyl;     wherein, each instance of heterocyclyl is optionally substituted     with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-carbonyl-oxy, wherein heterocyclyl is selected from     piperazinyl; and, wherein, each instance of heterocyclyl is     optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl-carbonyl-oxy selected from piperazin-1-yl-carbonyl-oxy;     wherein, each instance of heterocyclyl is optionally substituted     with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     C₃₋₁₄cycloalkyl selected from cyclopropyl, cyclobutyl, cyclopentyl,     cyclohexyl, cyclohexenyl or cycloheptyl; wherein, each instance of     C₃₋₁₄cycloalkyl is optionally substituted with R₃ and R₄     substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     C₃₋₈cycloalkyl selected from cyclopropyl, cyclobutyl, cyclopentyl,     cyclohexyl, cyclohexenyl or cycloheptyl; wherein, each instance of     C₃₋₈cycloalkyl is optionally substituted with R₃ and R₄     substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl, wherein aryl is selected from     phenyl; and, wherein, each instance of aryl is optionally     substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl selected from 3-(benzylamino)propyl;     wherein, each instance of aryl is optionally substituted with R₃ and     R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     heteroaryl, wherein heteroaryl is selected from pyridinyl; and,     wherein, each instance of heteroaryl is optionally substituted with     R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heteroaryl selected from pyridin-4-yl; wherein, each instance of     heteroaryl is optionally substituted with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     heteroaryl-C₁₋₈alkyl, wherein heteroaryl is selected from     1H-imidazolyl; and, wherein, each instance of heteroaryl is     optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heteroaryl-C₁₋₈alkyl selected from 1H-imidazol-1-yl-methyl; wherein,     each instance of heteroaryl is optionally substituted with R₃ and R₄     substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, wherein heteroaryl is     selected from pyridinyl; and, wherein, each instance of heteroaryl     is optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino selected from     (pyridin-3-ylmethyl)(methyl)amino; wherein, each instance of     heteroaryl is optionally substituted with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₁ is     heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl, wherein heteroaryl is selected     from thienyl or pyridinyl; and, wherein, each instance of heteroaryl     is optionally substituted with R₃ and R₄ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl selected from     thien-3-yl-methyl-amino-propyl, pyridin-2-yl-methyl-amino-propyl,     pyridin-3-yl-methyl-amino-propyl or     pyridin-4-yl-methyl-amino-propyl; wherein, each instance of     heteroaryl is optionally substituted with R₃ and R₄ substituents. -   In one aspect of the use of a compound of Formula (I), R₃ is     selected from cyano, halogen, hydroxy, oxo, C₁₋₈alkyl,     halo-C₁₋₈alkyl, C₁₋₈alkyl-carbonyl, C₁₋₈alkoxy, halo-C₁₋₈alkoxy,     C₁₋₈alkoxy-C₁₋₈alkyl, C₁₋₈alkoxy-carbonyl, amino, C₁₋₈alkyl-amino,     (C₁₋₈alkyl)₂-amino, amino-C₁₋₈alkyl, C₁₋₈alkyl-amino-C₁₋₈alkyl,     (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl, amino-C₁₋₈alkyl-amino,     C₁₋₈alkyl-amino-C₁₋₈alkyl-amino, (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     C₁₋₈alkoxy-C₁₋₈alkyl-amino, C₁₋₈alkyl-carbonyl-amino,     C₁₋₈alkoxy-carbonyl-amino, hydroxy-C₁₋₈alkyl,     hydroxy-C₁₋₈alkoxy-C₁₋₈alkyl, hydroxy-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl)₂-amino or (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino. -   In another aspect of the use of a compound of Formula (I), R₃ is     selected from cyano, halogen, hydroxy, oxo, C₁₋₈alkyl,     halo-C₁₋₈alkyl, C₁₋₈alkoxy, C₁₋₈alkoxy-C₁₋₈alkyl,     C₁₋₈alkoxy-carbonyl, amino, C₁₋₈alkyl-amino, (C₁₋₈alkyl)₂-amino,     amino-C₁₋₈alkyl, C₁₋₈alkyl-amino-C₁₋₈alkyl,     (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl, C₁₋₈alkyl-amino-C₁₋₈alkyl-amino,     C₁₋₈alkoxy-C₁₋₈alkyl-amino, C₁₋₈alkoxy-carbonyl-amino,     hydroxy-C₁₋₈alkyl, hydroxy-C₁₋₈alkoxy-C₁₋₈alkyl,     hydroxy-C₁₋₈alkyl-amino, (hydroxy-C₁₋₈alkyl)₂-amino or     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino. -   In one aspect of the use of a compound of Formula (I), R₃ is     C₁₋₈alkyl selected from methyl, ethyl, propyl, isopropyl or     tert-butyl. -   In another aspect of the use of a compound of Formula (I), R₃ is     C₁₋₈alkyl selected from ethyl, propyl, isopropyl or tert-butyl. -   In one aspect of the use of a compound of Formula (I), R₃ is     halo-C₁₋₈alkyl selected from trihalo-methyl, dihalo-methyl,     halo-methyl, trihalo-ethyl, dihalo-ethyl, halo-ethyl,     trihalo-propyl, dihalo-propyl or halo-propyl; wherein, halo is     selected from fluoro, chloro, bromo or iodo. -   In another aspect of the use of a compound of Formula (I), R₃ is     halo-C₁₋₈alkyl selected from trihalo-methyl, dihalo-methyl,     halo-methyl, trihalo-ethyl, dihalo-ethyl, trihalo-propyl or     dihalo-propyl; wherein, halo is selected from fluoro, chloro, bromo     or iodo. -   In one aspect of the use of a compound of Formula (I), R₃ is     hydroxy-C₁₋₈alkyl selected from hydroxy-methyl, hydroxy-ethyl,     hydroxy-propyl, dihydroxy-propyl, hydroxy-butyl or dihydroxy-butyl. -   In another aspect of the use of a compound of Formula (I), R₃ is     hydroxy-C₁₋₈alkyl selected from hydroxy-methyl, dihydroxy-propyl,     hydroxy-butyl or dihydroxy-butyl. -   In one aspect of the use of a compound of Formula (I), R₃ is     C₁₋₈alkoxy selected from methoxy, ethoxy, propoxy or isopropoxy. -   In one aspect of the use of a compound of Formula (I), R₃ is     halo-C₁₋₈alkoxy selected from trihalo-methoxy, dihalo-methoxy,     halo-methoxy, trihalo-ethoxy, dihalo-ethoxy, halo-ethoxy,     trihalo-propoxy, dihalo-propoxy or halo-propoxy; wherein, halo is     selected from fluoro, chloro, bromo or iodo. -   In one aspect of the use of a compound of Formula (I), R₃ is     C₁₋₈alkoxy-carbonyl-amino selected from methoxy-carbonyl-amino,     ethoxy-carbonyl-amino, propoxy-carbonyl-amino,     isopropoxy-carbonyl-amino, tert-butoxy-carbonyl-amino. -   In one aspect of the use of a compound of Formula (I), R₄ is     C₃₋₁₄cycloalkyl selected from cyclopropyl, cyclobutyl, cyclopentyl,     cyclohexyl or cycloheptyl; wherein, each instance of C₃₋₁₄cycloalkyl     is optionally substituted with R₅ substituents. -   In another aspect of the use of a compound of Formula (I), R₄ is     C₃₋₈cycloalkyl selected from cyclopropyl, cyclobutyl, cyclopentyl,     cyclohexyl or cycloheptyl; wherein, each instance of C₃₋₈cycloalkyl     is optionally substituted with R₅ substituents. -   In one aspect of the use of a compound of Formula (I), R₄ is     C₃₋₁₄cycloalkyl-C₁₋₈alkyl, wherein C₃₋₁₄cycloalkyl is selected from     cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl;     and, wherein, each instance of C₃₋₁₄cycloalkyl is optionally     substituted with R₅ substituents. -   In another aspect of the use of a compound of Formula (I), R₄ is     C₃₋₈cycloalkyl-C₁₋₈alkyl, wherein C₃₋₈cycloalkyl is selected from     cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl;     and, wherein, each instance of C₃₋₈cycloalkyl is optionally     substituted with R₅ substituents. -   In one aspect of the use of a compound of Formula (I), R₄ is     C₃₋₁₄cycloalkyl-amino, wherein C₃₋₁₄cycloalkyl is selected from     cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl;     and, wherein, each instance of C₃₋₁₄cycloalkyl is optionally     substituted with R₅ substituents. -   In another aspect of the use of a compound of Formula (I), R₄ is     C₃₋₈cycloalkyl-amino, wherein C₃₋₈cycloalkyl is selected from     cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl;     and, wherein, each instance of C₃₋₈cycloalkyl is optionally     substituted with R₅ substituents. -   In one aspect of the use of a compound of Formula (I), R₄ is     aryl-C₁₋₈alkyl, aryl-C₁₋₈alkoxy-carbonyl or     aryl-sulfonyloxy-C₁₋₈alkyl, wherein aryl is selected from phenyl;     and, wherein, each instance of aryl is optionally substituted with     R₅ substituents. -   In another aspect of the use of a compound of Formula (I), R₄ is     aryl-C₁₋₈alkyl or aryl-C₁₋₈alkoxy-carbonyl, wherein each instance of     aryl is optionally substituted with R₅ substituents. -   In one aspect of the use of a compound of Formula (I), R₄ is     heterocyclyl selected from oxetanyl, pyrrolidinyl, piperidinyl,     piperazinyl, 1,3-dioxanyl or morpholinyl, wherein each instance of     heterocyclyl is optionally substituted with R₅ substituents. -   In another aspect of the use of a compound of Formula (I), R₄ is     heterocyclyl selected from oxetan-3-yl, pyrrolidin-1-yl,     piperidin-1-yl, piperazin-1-yl, 1,3-dioxan-5-yl or morpholin-4-yl,     wherein each instance of heterocyclyl is optionally substituted with     R₅ substituents. -   In one aspect of the use of a compound of Formula (I), R₄ is     heterocyclyl-C₁₋₈alkyl, wherein each instance of heterocyclyl is     selected from pyrrolidinyl or piperidinyl; and, wherein, each     instance of heterocyclyl is optionally substituted with R₅     substituents. -   In another aspect of the use of a compound of Formula (I), R₄ is     heterocyclyl-C₁₋₈alkyl selected from pyrrolidin-1-yl-C₁₋₈alkyl or     piperidin-1-yl-C₁₋₈alkyl, wherein each instance of heterocyclyl is     optionally substituted with R₅ substituents. -   In one aspect of the use of a compound of Formula (I), R₅ is     selected from halogen, hydroxy, cyano, nitro, halo-C₁₋₈alkyl,     C₁₋₈alkoxy, halo-C₁₋₈alkoxy, amino, C₁₋₈alkyl-amino,     (C₁₋₈alkyl)₂-amino or C₁₋₈alkyl-thio; wherein, halogen and halo is     selected from fluoro, chloro, bromo or iodo. -   In one aspect of the use of a compound of Formula (I), R₅ is     hydroxy. -   In one aspect of the use of a compound of Formula (I), R₅ is     C₁₋₈alkyl selected from methyl, ethyl, propyl, isopropyl, n-butyl or     tert-butyl. -   In another aspect of the use of a compound of Formula (I), R₅ is     C₁₋₈alkyl selected from ethyl, propyl, isopropyl or tert-butyl. -   In one aspect of the use of a compound of Formula (I), R₅ is     halo-C₁₋₈alkyl selected from trihalo-methyl, dihalo-methyl,     halo-methyl, trihalo-ethyl, dihalo-ethyl, halo-ethyl,     trihalo-propyl, dihalo-propyl or halo-propyl; wherein, halo is     selected from fluoro, chloro, bromo or iodo. -   In one aspect of the use of a compound of Formula (I), R₅ is     C₁₋₈alkoxy selected from methoxy, ethoxy, propoxy or isopropoxy. -   In one aspect of the use of a compound of Formula (I), R₅ is     halo-C₁₋₈alkoxy selected from trihalo-methoxy, dihalo-methoxy,     halo-methoxy, trihalo-ethoxy, dihalo-ethoxy, halo-ethoxy,     trihalo-propoxy, dihalo-propoxy or halo-propoxy; wherein, halo is     selected from fluoro, chloro, bromo or iodo. -   In one aspect of the use of a compound of Formula (I), R₂ is aryl     selected from phenyl optionally substituted with one, two or three     R₆ substituents and optionally, with one additional R₇ substituent. -   In one aspect of the use of a compound of Formula (I), R₂ is     aryl-amino, wherein aryl is selected from phenyl; and, wherein, each     instance of aryl is optionally substituted with R₆ and R₇     substituents. -   In another aspect of the use of a compound of Formula (I), R₂ is     aryl-amino selected from phenyl-amino; wherein, each instance of     aryl is optionally substituted with R₆ and R₇ substituents. -   In one aspect of the use of a compound of Formula (I), R₂ is     aryl-amino-carbonyl, wherein aryl is selected from phenyl; and,     wherein, each instance of aryl is optionally substituted with R₆ and     R₇ substituents. -   In another aspect of the use of a compound of Formula (I), R₂ is     aryl-amino-carbonyl selected from phenyl-amino-carbonyl; wherein,     each instance of aryl is optionally substituted with R₆ and R₇     substituents. -   In one aspect of the use of a compound of Formula (I), -   R₂ is heterocyclyl selected from 1,2,3,6-tetrahydropyridinyl,     1,3-benzodioxolyl or 2,3-dihydro-1,4-benzodioxinyl; wherein, each     instance of heterocyclyl is optionally substituted with R₆ and R₇     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₂ is heterocyclyl selected from 1,2,3,6-tetrahydropyridin-4-yl,     1,3-benzodioxol-5-yl or 2,3-dihydro-1,4-benzodioxin-6-yl; wherein,     each instance of heterocyclyl is optionally substituted with R₆ and     R₇ substituents. -   In one aspect of the use of a compound of Formula (I), -   R₂ is heteroaryl optionally substituted with one, two or three R₆     substituents and optionally, with one additional R₇ substituent. -   In one aspect of the use of a compound of Formula (I), -   R₂ is heteroaryl selected from thienyl, 1H-pyrazolyl, 1H-imidazolyl,     1,3-thiazolyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, pyridinyl,     pyrimidinyl, 1H-indolyl, 2H-indolyl, 1H-indazolyl, 2H-indazolyl,     indolizinyl, benzofuranyl, benzothienyl, 1H-benzimidazolyl,     1,3-benzothiazolyl, 1,3-benzoxazolyl, 9H-purinyl, quinazolinyl,     quinoxalinyl, furo[3,2-b]pyridinyl, furo[3,2-c]pyridinyl,     furo[2,3-c]pyridinyl, thieno[3,2-c]pyridinyl,     thieno[2,3-d]pyrimidinyl, 1H-pyrrolo[2,3-b]pyridinyl,     1H-pyrrolo[2,3-c]pyridinyl, pyrrolo[1,2-a]pyrimidinyl,     pyrrolo[1,2-a]pyrazinyl, pyrrolo[1,2-b]pyridazinyl,     pyrazolo[1,5-a]pyridinyl, pyrazolo[1,5-a]pyrazinyl,     pyrazolo[4,3-b]pyridinyl, pyrazolo[3,4-c]pyridinyl,     imidazo[1,2-a]pyridinyl, 3H-imidazo[4,5-b]pyridinyl,     imidazo[1,2-a]pyrimidinyl, imidazo[1,2-c]pyrimidinyl,     imidazo[1,2-b]pyridazinyl, imidazo[1,2-a]pyrazinyl,     imidazo[2,1-b][1,3]thiazolyl, imidazo[2,1-b][1,3,4]thiadiazolyl,     [1,3]oxazolo[4,5-b]pyridinyl, [1,2,4]triazolo[1,5-a]pyridinyl,     [1,2,4]triazolo[4,3-a]pyridinyl, [1,2,4]triazolo[1,5-a]pyrimidinyl,     [1,2,4]triazolo[1,5-b]pyridazinyl, pyrido[1,2-a]pyrimidinyl or     pyrido[1,2-a]pyrimidinone; wherein, each instance of heteroaryl is     optionally substituted with one, two or three R₆ substituents and     optionally, with one additional R₇ substituent. -   In another aspect of the use of a compound of Formula (I), -   R₂ is heteroaryl selected from thien-2-yl, thien-3-yl,     1H-pyrazol-3-yl, 1H-pyrazol-4-yl, 1H-pyrazol-5-yl, 1H-imidazol-1-yl,     1H-imidazol-4-yl, 1,3-thiazol-2-yl, 1,2,4-oxadiazol-3-yl,     1,3,4-oxadiazol-2-yl, pyridin-2-yl, pyridin-3-yl, pyridin-4-yl,     pyrimidin-4-yl, 1H-indol-3-yl, 1H-indol-4-yl, 1H-indol-5-yl,     1H-indol-6-yl, 1H-indazol-5-yl, 2H-indazol-5-yl, indolizin-2-yl,     benzofuran-2-yl, benzofuran-5-yl, benzothien-2-yl, benzothien-3-yl,     1H-benzimidazol-2-yl, 1H-benzimidazol-6-yl, 1,3-benzoxazol-2-yl,     1,3-benzoxazol-5-yl, 1,3-benzoxazol-6-yl, 1,3-benzothiazol-2-yl,     1,3-benzothiazol-5-yl, 1,3-benzothiazol-6-yl, 9H-purin-8-yl,     quinazolin-6-yl, quinoxalin-2-yl, furo[3,2-b]pyridin-2-yl,     furo[3,2-c]pyridin-2-yl, furo[2,3-c]pyridin-2-yl,     thieno[3,2-c]pyridin-2-yl, thieno[2,3-d]pyrimidin-6-yl,     1H-pyrrolo[2,3-b]pyridin-5-yl, 1H-pyrrolo[2,3-c]pyridin-4-yl,     pyrrolo[1,2-a]pyrimidin-7-yl, pyrrolo[1,2-a]pyrazin-7-yl,     pyrrolo[1,2-b]pyridazin-2-yl, pyrazolo[1,5-a]pyridin-2-yl,     pyrazolo[1,5-a]pyridin-5-yl, pyrazolo[1,5-a]pyrazin-2-yl,     pyrazolo[4,3-b]pyridin-5-yl, pyrazolo[3,4-c]pyridin-5-yl,     imidazo[1,2-a]pyridin-2-yl, imidazo[1,2-a]pyridin-6-yl,     imidazo[1,2-a]pyrimidin-2-yl, imidazo[1,2-a]pyrimidin-6-yl,     imidazo[1,2-c]pyrimidin-2-yl, imidazo[1,2-b]pyridazin-2-yl,     imidazo[1,2-b]pyridazin-6-yl, imidazo[1,2-a]pyrazin-2-yl,     imidazo[2,1-b][1,3]thiazol-6-yl,     imidazo[2,1-b][1,3,4]thiadiazol-6-yl,     [1,3]oxazolo[4,5-b]pyridin-2-yl, [1,2,4]triazolo[1,5-a]pyridin-6-yl,     [1,2,4]triazolo[1,5-a]pyrimidin-6-yl,     [1,2,4]triazolo[1,5-b]pyridazin-6-yl, pyrido[1,2-a]pyrimidin-4-yl or     pyrido[1,2-a]pyrimidin-4-one; wherein, each instance of heteroaryl     is optionally substituted with one, two or three R₆ substituents and     optionally, with one additional R₇ substituent. -   In another aspect of the use of a compound of Formula (I), -   R₂ is substituted heteroaryl selected from 4-methylthien-2-yl,     1-methyl-1H-pyrazol-3-yl, 4-methyl-1H-pyrazol-3-yl,     1-phenyl-1H-pyrazol-3-yl,     1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl,     1-phenyl-1H-imidazol-4-yl,     2-methyl-1-(pyridin-2-yl)-1H-imidazol-4-yl,     4-methyl-1,3-thiazol-2-yl, 4-(trifluoromethyl)-1,3-thiazol-2-yl,     4-phenyl-1,3-thiazol-2-yl, 5-phenyl-1,2,4-oxadiazol-3-yl,     3-fluoropyridin-4-yl, 6-fluoropyridin-2-yl, 2-chloropyridin-4-yl,     4-chloropyridin-3-yl, 5-chloropyridin-2-yl, 6-methylpyridin-3-yl,     2-(trifluoromethyl)pyridin-3-yl, 4-(trifluoromethyl)pyridin-2-yl,     6-(trifluoromethyl)pyridin-2-yl, 2-methoxypyridin-4-yl,     4-methoxypyridin-3-yl, 6-methoxypyridin-2-yl, 2-ethoxypyridin-3-yl,     6-ethoxypyridin-2-yl, 6-(propan-2-yloxy)pyridin-2-yl,     6-(dimethylamino)pyridin-3-yl, 6-(methyl sulfanyl)pyridin-2-yl,     6-(cyclobutyloxy)pyridin-2-yl, 6-(pyrrolidin-1-yl)pyridin-2-yl,     (5-fluoro-6-hydroxy)pyridin-3-yl, 2-methylpyrimidin-4-yl,     2-(propan-2-yl)pyrimidin-4-yl, 2-cyclopropylpyrimidin-4-yl,     1-methyl-1H-indol-3-yl, 1,7-dimethyl-1H-indazol-5-yl,     2-methyl-2H-indazol-5-yl, 2,7-dimethyl-2H-indazol-5-yl,     7-fluoro-2-methyl-2H-indazol-5-yl, 2-methyl-1-benzofuran-5-yl,     1-methyl-1H-benzimidazol-2-yl, 4-methyl-1H-benzimidazol-2-yl     5-fluoro-1H-benzimidazol-2-yl, 4-fluoro-1,3-benzoxazol-2-yl,     5-fluoro-1,3-benzoxazol-2-yl, 4-chloro-1,3-benzoxazol-2-yl,     4-iodo-1,3-benzoxazol-2-yl, 2-methyl-1,3-benzoxazol-6-yl,     4-methyl-1,3-benzoxazol-2-yl,     4-(trifluoromethyl)-1,3-benzoxazol-2-yl,     7-(trifluoromethyl)-1,3-benzoxazol-2-yl,     2-methyl-1,3-benzothiazol-2-yl, 2-methyl-1,3-benzothiazol-5-yl,     2-methyl-1,3-benzothiazol-6-yl, 4-chloro-1,3-benzothiazol-2-yl,     7-chloro-1,3-benzothiazol-2-yl,     4-(trifluoromethyl)-1,3-benzothiazol-2-yl,     (4-hydroxy-2-methyl)quinazolin-6-yl,     5-methylfuro[3,2-b]pyridin-2-yl,     4,6-dimethylfuro[3,2-c]pyridin-2-yl,     5,7-dimethylfuro[2,3-c]pyridin-2-yl,     4,6-dimethylthieno[3,2-c]pyridin-2-yl,     2,4-dimethylthieno[2,3-d]pyrimidin-6-yl,     1-methylpyrrolo[1,2-a]pyrazin-7-yl,     3-methylpyrrolo[1,2-a]pyrazin-7-yl,     1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl,     2-methylpyrrolo[1,2-b]pyridazin-2-yl,     2-methylpyrazolo[1,5-a]pyridin-5-yl,     5-methylpyrazolo[1,5-a]pyridin-2-yl, 4-(dimethyl     amino)-6-methylpyrazolo[1,5-a]pyrazin-2-yl,     4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl,     4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl,     1,7-dimethyl-1H-pyrazolo[4,3-b]pyridin-5-yl,     1,7-dimethyl-1H-pyrazolo[3,4-c]pyridin-5-yl,     2,7-dimethyl-2H-pyrazolo[3,4-c]pyridin-5-yl,     2,7-dimethyl-2H-pyrazolo[4,3-b]pyridin-5-yl,     2-chloroimidazo[2,1-b][1,3]thiazol-6-yl,     2-methylimidazo[2,1-b][1,3]thiazol-6-yl,     3-methylimidazo[2,1-b][1,3]thiazol-6-yl,     2-ethylimidazo[2,1-b][1,3]thiazol-6-yl,     2-methylimidazo[2,1-b][1,3,4]thiadiazol-6-yl,     6-cyanoimidazo[1,2-a]pyridin-2-yl (also referred to as     2-imidazo[1,2-a]pyridine-6-carbonitrile),     6-fluoroimidazo[1,2-a]pyridin-2-yl,     8-fluoroimidazo[1,2-a]pyridin-2-yl,     6,8-difluoroimidazo[1,2-a]pyridin-2-yl,     7-(trifluoromethyl)imidazo[1,2-a]pyridin-2-yl,     8-(trifluoromethyl)imidazo[1,2-a]pyridin-2-yl,     6-chloroimidazo[1,2-a]pyridin-2-yl,     7-chloroimidazo[1,2-a]pyridin-2-yl,     8-chloroimidazo[1,2-a]pyridin-2-yl,     8-bromoimidazo[1,2-a]pyridin-2-yl,     2-methylimidazo[1,2-a]pyridin-2-yl,     5-methylimidazo[1,2-a]pyridin-2-yl,     6-methylimidazo[1,2-a]pyridin-2-yl,     7-methylimidazo[1,2-a]pyridin-2-yl,     8-methylimidazo[1,2-a]pyridin-2-yl,     7-ethylimidazo[1,2-a]pyridin-2-yl,     8-ethylimidazo[1,2-a]pyridin-2-yl,     6,8-dimethylimidazo[1,2-a]pyridin-2-yl,     8-ethyl-6-methylimidazo[1,2-a]pyridin-2-yl,     7-methoxyimidazo[1,2-a]pyridin-2-yl,     8-methoxyimidazo[1,2-a]pyridin-2-yl,     6-fluoro-8-methylimidazo[1,2-a]pyridin-2-yl,     8-fluoro-6-methylimidazo[1,2-a]pyridin-2-yl,     8-chloro-6-methylimidazo[1,2-a]pyridin-2-yl,     6-methyl-8-nitroimidazo[1,2-a]pyridin-2-yl,     8-cyclopropylimidazo[1,2-a]pyridin-2-yl,     2-methylimidazo[1,2-a]pyridin-6-yl,     2-ethylimidazo[1,2-a]pyridin-6-yl,     2,3-dimethylimidazo[1,2-a]pyridin-6-yl,     2,8-dimethylimidazo[1,2-a]pyridin-6-yl,     2-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl,     8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl,     8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl,     6-fluoroimidazo[1,2-a]pyrimidin-2-yl,     6-chloroimidazo[1,2-a]pyrimidin-2-yl,     6-methylimidazo[1,2-a]pyrimidin-2-yl,     7-methylimidazo[1,2-a]pyrimidin-2-yl,     2-methylimidazo[1,2-a]pyrimidin-6-yl,     6-methylimidazo[1,2-b]pyridazin-2-yl,     2-methylimidazo[1,2-b]pyridazin-6-yl,     2-methyl-3-(1,2,3,6-tetrahydropyridin-4-yl)imidazo[1,2-b]pyridazin-6-yl,     6-methylimidazo[1,2-a]pyrazin-2-yl,     8-methylimidazo[1,2-a]pyrazin-2-yl,     6,8-dimethylimidazo[1,2-a]pyrazin-2-yl,     6-chloro-8-methylimidazo[1,2-a]pyrazin-2-yl,     6-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyrazin-2-yl,     8-(methylsulfanyl)imidazo[1,2-a]pyrazin-2-yl,     2-methylimidazo[2,1-b][1,3]thiazol-6-yl,     3-methylimidazo[2,1-b][1,3]thiazol-6-yl,     2-methylimidazo[2,1-b][1,3,4]thiadiazol-6-yl,     2-methyl-[1,2,4]triazolo[1,5-a]pyridin-6-yl,     2-methyl-[1,2,4]triazolo[1,5-a]pyrimidin-6-yl,     2-methyl-[1,2,4]triazolo[1,5-b]pyridazin-6-yl or     4H,4′H-2,7′-bipyrido[1,2-a]pyrimidine-4,4′-dione. -   In another aspect of the use of a compound of Formula (I), -   R₂ is heteroaryl selected from thienyl, 1H-pyrazolyl, 1H-imidazolyl,     1,3-thiazolyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, pyridinyl,     pyrimidinyl, 1H-indolyl, 2H-indolyl, 1H-indazolyl, 2H-indazolyl,     indolizinyl, benzofuranyl, benzothienyl, 1H-benzimidazolyl,     1,3-benzothiazolyl, 1,3-benzoxazolyl, 9H-purinyl, quinazolinyl or     quinoxalinyl; wherein, each instance of heteroaryl is optionally     substituted with one, two or three R₆ substituents and optionally,     with one additional R₇ substituent. -   In another aspect of the use of a compound of Formula (I), -   R₂ is heteroaryl selected from furo[3,2-b]pyridinyl,     furo[3,2-c]pyridinyl, furo[2,3-c]pyridinyl, thieno[3,2-c]pyridinyl,     thieno[2,3-d]pyrimidinyl, 1H-pyrrolo[2,3-b]pyridinyl,     1H-pyrrolo[2,3-c]pyridinyl, pyrrolo[1,2-a]pyrimidinyl,     pyrrolo[1,2-a]pyrazinyl, pyrrolo[1,2-b]pyridazinyl,     pyrazolo[1,5-a]pyridinyl, pyrazolo[1,5-a]pyrazinyl,     pyrazolo[4,3-b]pyridinyl, pyrazolo[3,4-c]pyridinyl,     imidazo[1,2-a]pyridinyl, 3H-imidazo[4,5-b]pyridinyl,     imidazo[1,2-a]pyrimidinyl, imidazo[1,2-c]pyrimidinyl,     imidazo[1,2-b]pyridazinyl, imidazo[1,2-a]pyrazinyl,     imidazo[2,1-b][1,3]thiazolyl, imidazo[2,1-b][1,3,4]thiadiazolyl,     [1,3]oxazolo[4,5-b]pyridinyl, [1,2,4]triazolo[1,5-a]pyridinyl,     [1,2,4]triazolo[4,3-a]pyridinyl, [1,2,4]triazolo[1,5-a]pyrimidinyl,     [1,2,4]triazolo[1,5-b]pyridazinyl, pyrido[1,2-a]pyrimidinyl or     pyrido[1,2-a]pyrimidinone; wherein, each instance of heteroaryl is     optionally substituted with one, two or three R₆ substituents and     optionally, with one additional R₇ substituent. -   In one aspect of the use of a compound of Formula (I), R₂ is     heteroaryl-amino, wherein heteroaryl is selected from pyridinyl or     pyrimidinyl; and, wherein, each instance of heteroaryl is optionally     substituted with R₆ and R₇ substituents. -   In another aspect of the use of a compound of Formula (I), R₂ is     heteroaryl-amino selected from pyridin-2-yl-amino,     pyridin-3-yl-amino or pyrimidin-2-yl-amino; wherein, each instance     of heteroaryl is optionally substituted with R₆ and R₇ substituents. -   In one aspect of the use of a compound of Formula (I), R₆ is     selected from halogen, hydroxy, cyano, nitro, C₁₋₈alkyl,     halo-C₁₋₈alkyl, hydroxy-C₁₋₈alkyl, C₁₋₈alkoxy, halo-C₁₋₈alkoxy,     C₁₋₈alkoxy-C₁₋₈alkyl, (C₁₋₈alkyl)₂-amino or C₁₋₈alkyl-thio; wherein,     halogen and halo is selected from fluoro, chloro, bromo or iodo. -   In one aspect of the use of a compound of Formula (I), R₆ is     C₁₋₈alkyl selected from methyl, ethyl, propyl, isopropyl or     tert-butyl. -   In another aspect of the use of a compound of Formula (I), R₆ is     C₁₋₈alkyl selected from ethyl, propyl, isopropyl or tert-butyl. -   In one aspect of the use of a compound of Formula (I), R₆ is     C₂₋₈alkenyl selected from ethenyl, allyl or buta-1,3-dienyl. -   In another aspect of the use of a compound of Formula (I), R₆ is     C₂₋₈alkenyl selected from ethenyl or allyl. -   In one aspect of the use of a compound of Formula (I), R₆ is     halo-C₁₋₈alkyl selected from trihalo-methyl, dihalo-methyl,     halo-methyl, trihalo-ethyl, dihalo-ethyl, halo-ethyl,     trihalo-propyl, dihalo-propyl or halo-propyl; wherein, halo is     selected from fluoro, chloro, bromo or iodo. -   In one aspect of the use of a compound of Formula (I), R₆ is     hydroxy-C₁₋₈alkyl selected from hydroxy-methyl, hydroxy-ethyl,     hydroxy-propyl, dihydroxy-propyl, hydroxy-butyl or dihydroxy-butyl. -   In another aspect of the use of a compound of Formula (I), R₆ is     hydroxy-C₁₋₈alkyl selected from hydroxy-methyl, dihydroxy-propyl,     hydroxy-butyl or dihydroxy-butyl. -   In one aspect of the use of a compound of Formula (I), R₆ is     C₁₋₈alkoxy selected from methoxy, ethoxy, propoxy or isopropoxy. -   In one aspect of the use of a compound of Formula (I), R₆ is     halo-C₁₋₈alkoxy selected from trihalo-methoxy, dihalo-methoxy,     halo-methoxy, trihalo-ethoxy, dihalo-ethoxy, halo-ethoxy,     trihalo-propoxy, dihalo-propoxy or halo-propoxy; wherein, halo is     selected from fluoro, chloro, bromo or iodo. -   In one aspect of the use of a compound of Formula (I), R₇ is     C₃₋₁₄cycloalkyl, C₃₋₁₄cycloalkyl-oxy, aryl, heterocyclyl or     heteroaryl; wherein C₃₋₁₄cycloalkyl is selected from cyclopropyl or     cyclobutoxy; wherein aryl is selected from phenyl; wherein     heterocyclyl is selected from oxetanyl, pyrrolidinyl or     1,2,3,6-tetrahydropyridinyl; and, wherein heteroaryl is selected     from thienyl or pyridinyl. -   In another aspect of the use of a compound of Formula (I), R₇ is     C₃₋₁₄cycloalkyl or C₃₋₁₄cycloalkyl-oxy, wherein each instance of     C₃₋₁₄cycloalkyl is selected from cyclopropyl, cyclobutyl,     cyclopentyl, cyclohexyl or cycloheptyl. -   In another aspect of the use of a compound of Formula (I), R₇ is     C₃₋₈cycloalkyl or C₃₋₈cycloalkyl-oxy, wherein each instance of     C₃₋₈cycloalkyl is selected from cyclopropyl, cyclobutyl,     cyclopentyl, cyclohexyl or cycloheptyl. -   In one aspect of the use of a compound of Formula (I), R₇ is aryl     selected from phenyl. -   In one aspect of the use of a compound of Formula (I), R₇ is     heterocyclyl selected from oxetanyl, pyrrolidinyl or     1,2,3,6-tetrahydropyridinyl. -   In another aspect of the use of a compound of Formula (I), R₇ is     heterocyclyl selected from oxetan-3-yl, pyrrolidin-1-yl or     1,2,3,6-tetrahydropyridin-4-yl. -   In one aspect of the use of a compound of Formula (I), R₇ is     heteroaryl selected from thienyl or pyridinyl. -   In another aspect of the use of a compound of Formula (I), R₇ is     heteroaryl selected from pyridinyl. -   In one aspect of the use of a compound of Formula (I), R₇ is     heteroaryl selected from thien-2-yl or pyridin-2-yl. -   In another aspect of the use of a compound of Formula (I), R₇ is     heteroaryl selected from pyridin-2-yl. -   In one aspect of the use of a compound of Formula (I), R_(c) is     hydrogen or C₁₋₈alkyl. -   In another aspect of the use of a compound of Formula (I), -   R₁ is heterocyclyl, heterocyclyl-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkoxy,     heterocyclyl-amino, (heterocyclyl)(C₁₋₈alkyl)amino,     heterocyclyl-amino-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkyl-amino,     (heterocyclyl-C₁₋₈alkyl)₂-amino,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     heterocyclyl-oxy, heterocyclyl-carbonyl, heterocyclyl-carbonyl-oxy,     C₃₋₁₄cycloalkyl, aryl-C₁₋₈alkyl-amino, (aryl-C₁₋₈alkyl)₂-amino,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl, heteroaryl,     heteroaryl-C₁₋₈alkyl, heteroaryl-C₁₋₈alkoxy, heteroaryl-amino,     heteroaryl-C₁₋₈alkyl-amino, (heteroaryl-C₁₋₈alkyl)₂-amino,     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heteroaryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; wherein, each     instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and heteroaryl is     optionally substituted with R₃ and R₄ substituents; and, -   wherein, heterocyclyl is selected from azetidinyl,     tetrahydrofuranyl, pyrrolidinyl, piperidinyl, piperazinyl,     1,4-diazepanyl, 3,6-dihydropyridinyl, 1,2,5,6-tetrahydropyridinyl,     1,2,3,6-tetrahydropyridinyl, hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl,     (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl,     (3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl,     hexahydropyrrolo[3,4-b]pyrrol-(2H)-yl,     (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-(2H)-yl,     hexahydropyrrolo[3,4-c]pyrrol-(1H)-yl,     (3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-(1H)-yl,     octahydro-5H-pyrrolo[3,2-c]pyridinyl,     octahydro-6H-pyrrolo[3,4-b]pyridinyl,     (4aR,7aR)-octahydro-6H-pyrrolo[3,4-b]pyridinyl,     (4aS,7aS)-octahydro-6H-pyrrolo[3,4-b]pyridinyl,     hexahydropyrrolo[1,2-a]pyrazin-(2H)-one,     hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (7R,8aS)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aS)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aR)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aS)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazinyl,     (8aR)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazinyl,     (8aS)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazinyl,     (8aR)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazinyl,     (8aS)-octahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aR)-octahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     octahydro-2H-pyrido[1,2-a]pyrazinyl,     (3aR,4aR,7aS)-hexahydro-1H-cyclobuta[1,2-c:1,4-c′]dipyrrol-(3H)-yl,     3-azabicyclo[3.1.0]hexyl, (1R,5S)-3-azabicyclo[3.1.0]hexyl,     8-azabicyclo[3.2.1]octyl, (1R,5S)-8-azabicyclo[3.2.1]octyl,     8-azabicyclo[3.2.1]oct-2-enyl,     (1R,5S)-8-azabicyclo[3.2.1]oct-2-enyl, 9-azabicyclo[3.3.1]nonyl,     (1R,5S)-9-azabicyclo[3.3.1]nonyl, 2,5-diazabicyclo[2.2.1]heptyl,     (1S,4S)-2,5-diazabicyclo[2.2.1]heptyl, 2,5-diazabicyclo[2.2.2]octyl,     3,6-diazabicyclo[3.2.0]hept-3-yl, 3,8-diazabicyclo[3.2.1]octyl,     (1R,5S)-3,8-diazabicyclo[3.2.1]octyl, 1,4-diazabicyclo[3.2.2]nonyl,     azaspiro[3.3]heptyl, 2,6-diazaspiro[3.3]heptyl,     4,7-diazaspiro[2.5]oct-7-yl, 2,6-diazaspiro[3.4]oct-2-yl,     2,7-diazaspiro[3.5]nonyl, 5,8-diazaspiro[3.5]nonyl,     2,7-diazaspiro[4.4]nonyl or 6,9-diazaspiro[4.5]decyl. -   In another aspect of the use of a compound of Formula (I), -   R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl,     heteroaryl or heteroaryl-amino; -   wherein, aryl is phenyl; -   wherein, heterocyclyl is selected from 1,2,3,6-tetrahydropyridinyl,     1,3-benzodioxolyl or 2,3-dihydro-1,4-benzodioxinyl; -   wherein, heteroaryl is selected from thienyl, 1H-pyrazolyl,     1H-imidazolyl, 1,3-thiazolyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl,     pyridinyl, pyrimidinyl, 1H-indolyl, 2H-indolyl, 1H-indazolyl,     2H-indazolyl, indolizinyl, benzofuranyl, benzothienyl,     1H-benzimidazolyl, 1,3-benzothiazolyl, 1,3-benzoxazolyl, 9H-purinyl,     quinazolinyl, quinoxalinyl, furo[3,2-b]pyridinyl,     furo[3,2-c]pyridinyl, furo[2,3-c]pyridinyl, thieno[3,2-c]pyridinyl,     thieno[2,3-d]pyrimidinyl, 1H-pyrrolo[2,3-b]pyridinyl,     1H-pyrrolo[2,3-c]pyridinyl, pyrrolo[1,2-a]pyrimidinyl,     pyrrolo[1,2-a]pyrazinyl, pyrrolo[1,2-b]pyridazinyl,     pyrazolo[1,5-a]pyridinyl, pyrazolo[1,5-a]pyrazinyl,     pyrazolo[4,3-b]pyridinyl, pyrazolo[3,4-c]pyridinyl,     imidazo[1,2-a]pyridinyl, imidazo[1,2-a]pyrimidinyl,     imidazo[1,2-c]pyrimidinyl, imidazo[1,2-b]pyridazinyl,     imidazo[1,2-a]pyrazinyl, imidazo[2,1-b][1,3]thiazolyl,     imidazo[2,1-b][1,3,4]thiadiazolyl, [1,3]oxazolo[4,5-b]pyridinyl,     [1,2,4]triazolo[1,5-a]pyridinyl, [1,2,4]triazolo[1,5-a]pyrimidinyl,     [1,2,4]triazolo[1,5-b]pyridazinyl, pyrido[1,2-a]pyrimidinyl or     pyrido[1,2-a]pyrimidinone; and, wherein, each instance of aryl,     heterocyclyl and heteroaryl is optionally substituted with R₆ and R₇     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is heterocyclyl, heterocyclyl-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkoxy,     heterocyclyl-amino, (heterocyclyl)(C₁₋₈alkyl)amino,     heterocyclyl-amino-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkyl-amino,     (heterocyclyl-C₁₋₈alkyl)₂-amino,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     heterocyclyl-oxy, heterocyclyl-carbonyl, heterocyclyl-carbonyl-oxy,     C₃₋₁₄cycloalkyl, aryl-C₁₋₈alkyl-amino, (aryl-C₁₋₈alkyl)₂-amino,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl, heteroaryl,     heteroaryl-C₁₋₈alkyl, heteroaryl-C₁₋₈alkoxy, heteroaryl-amino,     heteroaryl-C₁₋₈alkyl-amino, (heteroaryl-C₁₋₈alkyl)₂-amino,     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heteroaryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; -   wherein, heterocyclyl is selected from azetidinyl,     tetrahydrofuranyl, pyrrolidinyl, piperidinyl, piperazinyl,     1,4-diazepanyl, 3,6-dihydropyridinyl, 1,2,5,6-tetrahydropyridinyl,     1,2,3,6-tetrahydropyridinyl, hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl,     (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl,     (3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl,     hexahydropyrrolo[3,4-b]pyrrol-(2H)-yl,     (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-(2H)-yl,     hexahydropyrrolo[3,4-c]pyrrol-(1H)-yl,     1,3,3a,4,6,6a-hexahydropyrrolo[3,4-c]pyrrolyl,     (3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-(1H)-yl,     octahydro-5H-pyrrolo[3,2-c]pyridinyl,     octahydro-6H-pyrrolo[3,4-b]pyridinyl,     (4aR,7aR)-octahydro-6H-pyrrolo[3,4-b]pyridinyl,     (4aS,7aS)-octahydro-6H-pyrrolo[3,4-b]pyridinyl,     hexahydropyrrolo[1,2-a]pyrazin-(2H)-one,     hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (7R,8aS)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aS)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aR)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aS)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazinyl,     (8aR)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazinyl,     (8aS)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazinyl,     (8aR)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazinyl,     (8aS)-octahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     (8aR)-octahydropyrrolo[1,2-a]pyrazin-(1H)-yl,     octahydro-2H-pyrido[1,2-a]pyrazinyl,     (3aR,4aR,7aS)-hexahydro-1H-cyclobuta[1,2-c:1,4-c′]dipyrrol-(3H)-yl,     3-azabicyclo[3.1.0]hexyl, (1R,5S)-3-azabicyclo[3.1.0]hexyl,     8-azabicyclo[3.2.1]octyl, (1R,5S)-8-azabicyclo[3.2.1]octyl,     8-azabicyclo[3.2.1]oct-2-enyl,     (1R,5S)-8-azabicyclo[3.2.1]oct-2-enyl, 9-azabicyclo[3.3.1]nonyl,     (1R,5S)-9-azabicyclo[3.3.1]nonyl, 2,5-diazabicyclo[2.2.1]heptyl,     (1S,4S)-2,5-diazabicyclo[2.2.1]heptyl, 2,5-diazabicyclo[2.2.2]octyl,     3,6-diazabicyclo[3.2.0]heptyl, 3,8-diazabicyclo[3.2.1]octyl,     (1R,5S)-3,8-diazabicyclo[3.2.1]octyl, 1,4-diazabicyclo[3.2.2]nonyl,     azaspiro[3.3]heptyl, 2,6-diazaspiro[3.3]heptyl,     4,7-diazaspiro[2.5]octyl, 2,6-diazaspiro[3.4]octyl,     2,7-diazaspiro[3.5]nonyl, 5,8-diazaspiro[3.5]nonyl,     2,7-diazaspiro[4.4]nonyl or 6,9-diazaspiro[4.5]decyl; and, wherein,     each instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and heteroaryl     is optionally substituted with R₃ and R₄ substituents; and -   R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl,     heteroaryl or heteroaryl-amino; -   wherein, heterocyclyl is selected from     1,2,3,6-tetrahydropyridin-4-yl, 1,3-benzodioxol-5-yl or     2,3-dihydro-1,4-benzodioxin-6-yl; -   wherein, heteroaryl is selected from thienyl, 1H-pyrazolyl,     1H-imidazolyl, 1,3-thiazolyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl,     pyridinyl, pyrimidinyl, 1H-indolyl, 2H-indolyl, 1H-indazolyl,     2H-indazolyl, indolizinyl, benzofuranyl, benzothienyl,     1H-benzimidazolyl, 1,3-benzothiazolyl, 1,3-benzoxazolyl, 9H-purinyl,     quinazolinyl, quinoxalinyl, furo[3,2-b]pyridinyl,     furo[3,2-c]pyridinyl, furo[2,3-c]pyridinyl, thieno[3,2-c]pyridinyl,     thieno[2,3-d]pyrimidinyl, 1H-pyrrolo[2,3-b]pyridinyl,     1H-pyrrolo[2,3-c]pyridinyl, pyrrolo[1,2-a]pyrimidinyl,     pyrrolo[1,2-a]pyrazinyl, pyrrolo[1,2-b]pyridazinyl,     pyrazolo[1,5-a]pyridinyl, pyrazolo[1,5-a]pyrazinyl,     pyrazolo[4,3-b]pyridinyl, pyrazolo[3,4-c]pyridinyl,     imidazo[1,2-a]pyridinyl, 3H-imidazo[4,5-b]pyridinyl,     imidazo[1,2-a]pyrimidinyl, imidazo[1,2-c]pyrimidinyl,     imidazo[1,2-b]pyridazinyl, imidazo[1,2-a]pyrazinyl,     imidazo[2,1-b][1,3]thiazolyl, imidazo[2,1-b][1,3,4]thiadiazolyl,     [1,3]oxazolo[4,5-b]pyridinyl, [1,2,4]triazolo[1,5-a]pyridinyl,     [1,2,4]triazolo[4,3-a]pyridinyl, [1,2,4]triazolo[1,5-a]pyrimidinyl,     [1,2,4]triazolo[1,5-b]pyridazinyl, pyrido[1,2-a]pyrimidinyl or     pyrido[1,2-a]pyrimidinone; and, wherein, each instance of     heterocyclyl and heteroaryl is optionally substituted with R₆ and R₇     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is C₁₋₈alkyl, amino, C₁₋₈alkyl-amino, (C₁₋₈alkyl)₂-amino,     C₁₋₈alkoxy-C₁₋₈alkyl-amino, (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino, amino-C₁₋₈alkyl,     C₁₋₈alkyl-amino-C₁₋₈alkyl, (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     amino-C₁₋₈alkyl-amino, (amino-C₁₋₈alkyl)₂-amino,     (amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino, C₁₋₈alkyl-amino-C₁₋₈alkyl-amino,     (C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino,     (C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     [(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino, amino-C₁₋₈alkoxy,     C₁₋₈alkyl-amino-C₁₋₈alkoxy, (C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy,     (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy,     amino-C₂₋₈alkenyl, C₁₋₈alkyl-amino-C₂₋₈alkenyl,     (C₁₋₈alkyl)₂-amino-C₂₋₈alkenyl, amino-C₂₋₈alkynyl,     C₁₋₈alkyl-amino-C₂₋₈alkynyl, (C₁₋₈alkyl)₂-amino-C₂₋₈alkynyl,     halo-C₁₋₈alkyl-amino, (halo-C₁₋₈alkyl)₂-amino,     (halo-C₁₋₈alkyl)(C₁₋₈alkyl)amino, hydroxy-C₁₋₈alkyl,     hydroxy-C₁₋₈alkoxy-C₁₋₈alkyl, hydroxy-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl)₂-amino, (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy,     hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino,     (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino,     (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl-amino,     [(hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino or     [(hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl](C₁₋₈alkyl)amino; and     R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl,     heteroaryl or heteroaryl-amino, wherein, each instance of aryl,     heterocyclyl and heteroaryl is optionally substituted with R₆ and R₇     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is heterocyclyl, heterocyclyl-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkoxy,     heterocyclyl-amino, (heterocyclyl)(C₁₋₈alkyl)amino,     heterocyclyl-amino-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkyl-amino,     (heterocyclyl-C₁₋₈alkyl)₂-amino,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     heterocyclyl-oxy, heterocyclyl-carbonyl, heterocyclyl-carbonyl-oxy,     C₃₋₁₄cycloalkyl, aryl-C₁₋₈alkyl-amino, (aryl-C₁₋₈alkyl)₂-amino,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl, heteroaryl,     heteroaryl-C₁₋₈alkyl, heteroaryl-C₁₋₈alkoxy, heteroaryl-amino,     heteroaryl-C₁₋₈alkyl-amino, (heteroaryl-C₁₋₈alkyl)₂-amino,     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heteroaryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; wherein, each     instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and heteroaryl is     optionally substituted with R₃ and R₄ substituents; and -   R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl,     heteroaryl or heteroaryl-amino, wherein, each instance of aryl,     heterocyclyl and heteroaryl is optionally substituted with R₆ and R₇     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is heterocyclyl, heterocyclyl-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkoxy,     heterocyclyl-amino, (heterocyclyl)(C₁₋₈alkyl)amino,     heterocyclyl-amino-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkyl-amino,     (heterocyclyl-C₁₋₈alkyl)₂-amino,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl,     (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl,     heterocyclyl-oxy, heterocyclyl-carbonyl or     heterocyclyl-carbonyl-oxy; wherein, each instance of heterocyclyl is     optionally substituted with R₃ and R₄ substituents; and R₂ is aryl,     aryl-amino, aryl-amino-carbonyl, heterocyclyl, heteroaryl or     heteroaryl-amino, wherein, each instance of aryl, heterocyclyl and     heteroaryl is optionally substituted with -   R₆ and R₇ substituents. -   In another aspect of the use of a compound of Formula (I), R₁ is     heterocyclyl optionally substituted with one, two or three R₃     substituents and optionally, with one additional R₄ substituents;     or, optionally, with one, two, three or four R₃ substituents; and -   R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl,     heteroaryl or heteroaryl-amino, wherein, each instance of aryl,     heterocyclyl and heteroaryl is optionally substituted with R₆ and R₇     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is C₃₋₁₄cycloalkyl optionally substituted with R₃ and R₄     substituents; and -   R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl,     heteroaryl or heteroaryl-amino, wherein, each instance of aryl,     heterocyclyl and heteroaryl is optionally substituted with R₆ and R₇     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is aryl-C₁₋₈alkyl-amino, (aryl-C₁₋₈alkyl)₂-amino,     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (aryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or     (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; wherein, each instance     of aryl is optionally substituted with R₃ and R₄ substituents; and     R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl,     heteroaryl or heteroaryl-amino, wherein, each instance of aryl,     heterocyclyl and heteroaryl is optionally substituted with R₆ and R₇     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is aryl-C₁₋₈alkyl-amino optionally substituted with R₃ and R₄     substituents; and -   R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl,     heteroaryl or heteroaryl-amino, wherein, each instance of aryl,     heterocyclyl and heteroaryl is optionally substituted with R₆ and R₇     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is heteroaryl, heteroaryl-C₁₋₈alkyl, heteroaryl-C₁₋₈alkoxy,     heteroaryl-amino, heteroaryl-C₁₋₈alkyl-amino,     (heteroaryl-C₁₋₈alkyl)₂-amino,     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino,     heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl,     (heteroaryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or     (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; wherein, each     instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and heteroaryl is     optionally substituted with R₃ and R₄ substituents; and -   R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl,     heteroaryl or heteroaryl-amino, wherein, each instance of aryl,     heterocyclyl and heteroaryl is optionally substituted with R₆ and R₇     substituents. -   In another aspect of the use of a compound of Formula (I), -   R₁ is heteroaryl optionally substituted with R₃ and R₄ substituents;     and -   R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl,     heteroaryl or heteroaryl-amino, wherein, each instance of aryl,     heterocyclyl and heteroaryl is optionally substituted with R₆ and R₇     substituents. -   An aspect of the use of the compound of Formula (I) is the use of a     compound selected from Formula (II), Formula (III), Formula (IV),     Formula (V), Formula (VI), Formula (VII), Formula (VIII), Formula     (IX), Formula (X), Formula (XI), Formula (XII), Formula (XIII) or     Formula (XIV):

-   or a form thereof. -   In an aspect of the use of the compound of Formula (I), w₃ is C—R₁,     w₆ is C—R₂, w₁, w₄, w₅ and w₇ are independently C—R_(a) or N and w₂     is C—R_(b) or N. -   In another aspect of the use of the compound of Formula (I), w₃ is     C—R₂, w₆ is C—R₁, w₁, w₄, w₅ and w₇ are independently C—R_(a) or N     and w₂ is C—R_(b) or N. -   In another aspect of the use of the compound of Formula (I), w₄ is     C—R₁, w₇ is C—R₂, w₁, w₃ and w₅ are independently C—R_(a) or N, w₂     is C—R_(b) or N and w₆ is C—R_(e) or N. -   In another aspect of the use of the compound of Formula (I), w₄ is     C—R₂, w₇ is C—R₁, w₁, w₃ and w₅ are independently C—R_(a) or N, w₂     is C—R_(b) or N and w₆ is C—R_(e) or N. -   In an aspect of the use of the compound of Formula (II), w₃ is C—R₁,     w₆ is C—R₂, w₄, w₅ and w₇ are independently C—R_(a) or N and w₂ is     C—R_(b) or N. -   In another aspect of the use of the compound of Formula (II), w₃ is     C—R₂, w₆ is C—R₁, w₄, w₅ and w₇ are independently C—R_(a) or N and     w₂ is C—R_(b) or N. -   In another aspect of the use of the compound of Formula (II), w₄ is     C—R₁, w₇ is C—R₂, w₃ and w₅ are independently C—R_(a) or N, w₂ is     C—R_(b) or N and w₆ is C—R_(e) or N. -   In another aspect of the use of the compound of Formula (II), w₄ is     C—R₂, w₇ is C—R₁, w₃ and w₅ are independently C—R_(a) or N, w₂ is     C—R_(b) or N and w₆ is C—R_(e) or N. -   In an aspect of the use of the compound of Formula (III), w₃ is     C—R₁, w₆ is C—R₂ and w₁, w₄, w₅ and w₇ are independently C—R_(a) or     N. -   In another aspect of the use of the compound of Formula (III), w₃ is     C—R₂, w₆ is C—R₁ and w₁, w₄, w₅ and w₇ are independently C—R_(a) or     N. -   In another aspect of the use of the compound of Formula (III), w₄ is     C—R₁, w₇ is C—R₂, w₁, w₃ and w₅ are independently C—R_(a) or N and     w₆ is C—R_(e) or N. -   In another aspect of the use of the compound of Formula (III), w₄ is     C—R₂, w₇ is C—R₁, w₁, w₃ and w₅ are independently C—R_(a) or N and     w₆ is C—R_(e) or N. -   In an aspect of the use of the compound of Formula (IV), w₄ is C—R₁,     w₇ is C—R₂, w₁ and w₅ are independently C—R_(a) or N, w₂ is C—R_(b)     or N and w₆ is C—R_(e) or N. -   In another aspect of the use of the compound of Formula (IV), w₄ is     C—R₂, w₇ is C—R₁, w₁ and w₅ are independently C—R_(a) or N, w₂ is     C—R_(b) or N and w₆ is C—R_(e) or N. -   In an aspect of the use of the compound of Formula (V), w₃ is C—R₁,     w₆ is C—R₂, w₁, w₅ and w₇ are independently C—R_(a) or N and w₂ is     C—R_(b) or N. -   In another aspect of the use of the compound of Formula (V), w₃ is     C—R₂, w₆ is C—R₁, w₁, w₅ and w₇ are independently C—R_(a) or N and     w₂ is C—R_(b) or N. -   In an aspect of the use of the compound of Formula (VI), w₃ is C—R₁,     w₆ is C—R₂, w₁, w₄ and w₇ are independently C—R_(a) or N and w₂ is     C—R_(b) or N. -   In another aspect of the use of the compound of Formula (VI), w₃ is     C—R₂, w₆ is C—R₁, w₁, w₄ and w₇ are independently C—R_(a) or N and     w₂ is C—R_(b) or N. -   In another aspect of the use of the compound of Formula (VI), w₄ is     C—R₁, w₇ is C—R₂, w₁ and w₃ are independently C—R_(a) or N, w₂ is     C—R_(b) or N and w₆ is C—R_(e) or N. -   In another aspect of the use of the compound of Formula (VI), w₄ is     C—R₂, w₇ is C—R₁, w₁ and w₃ are independently C—R_(a) or N, w₂ is     C—R_(b) or N and w₆ is C—R_(e) or N. -   In another aspect of the use of the compound of Formula (VII), w₄ is     C—R₁, w₇ is C—R₂, w₁, w₃ and w₅ are C—R_(a) or N and w₂ is C—R_(b)     or N. -   In another aspect of the use of the compound of Formula (VII), w₄ is     C—R₂, w₇ is C—R₁, w₁, w₃ and w₅ are C—R_(a) or N and w₂ is C—R_(b)     or N. -   In another aspect of the use of the compound of Formula (VIII), w₃     is C—R₁, w₆ is C—R₂, w₁, w₄ and w₅ are C—R_(a) or N and w₂ is     C—R_(b) or N. -   In another aspect of the use of the compound of Formula (VIII), w₃     is C—R₂, w₆ is C—R₁, w₁, w₄ and w₅ are C—R_(a) or N and w₂ is     C—R_(b) or N. -   In an aspect of the use of the compound of Formula (IX), w₃ is C—R₁,     w₆ is C—R₂, w₄ and w₇ are independently C—R_(a) or N and w₂ is     C—R_(b) or N. -   In another aspect of the use of the compound of Formula (IX), w₃ is     C—R₂, w₆ is C—R₁, w₄ and w₇ are independently C—R_(a) or N and w₂ is     C—R_(b) or N. -   In another aspect of the use of the compound of Formula (IX), w₄ is     C—R₁, w₇ is C—R₂, w₂ is C—R_(b) or N, w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N. -   In another aspect of the use of the compound of Formula (IX), w₄ is     C—R₂, w₇ is C—R₁, w₂ is C—R_(b) or N, w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N. -   In an aspect of the use of the compound of Formula (X), w₃ is C—R₁,     w₆ is C—R₂, w₂ is C—R_(b) or N and w₅ and w₇ are independently     C—R_(a) or N. -   In another aspect of the use of the compound of Formula (X), w₃ is     C—R₂, w₆ is C—R₁, w₂ is C—R_(b) or N and w₅ and w₇ are independently     C—R_(a) or N. -   In an aspect of the use of the compound of Formula (XI), w₄ is C—R₁,     w₇ is C—R₂, w₂ is C—R_(b) or N, w₅ is C—R_(a) or N and w₆ is C—R_(e)     or N. -   In another aspect of the use of the compound of Formula (XI), w₄ is     C—R₂, w₇ is C—R₁, w₂ is C—R_(b) or N, w₅ is C—R_(a) or N and w₆ is     C—R_(e) or N. -   In an aspect of the use of the compound of Formula (XII), w₃ is     C—R₁, w₆ is C—R₂ and w₄, w₅ and w₇ are independently C—R_(a) or N. -   In another aspect of the use of the compound of Formula (XII), w₃ is     C—R₂, w₆ is C—R₁ and w₄, w₅ and w₇ are independently C—R_(a) or N. -   In another aspect of the use of the compound of Formula (XII), w₄ is     C—R₁, w₇ is C—R₂, w₃ and w₅ are independently C—R_(a) or N and w₆ is     C—R_(e) or N. -   In another aspect of the use of the compound of Formula (XII), w₄ is     C—R₂, w₇ is C—R₁, w₃ and w₅ are independently C—R_(a) or N and w₆ is     C—R_(e) or N. -   In an aspect of the use of the compound of Formula (XIII), w₃ is     C—R₁, w₆ is C—R₂, w₂ is C—R_(b) or N and w₄ and w₅ are independently     C—R_(a) or N. -   In another aspect of the use of the compound of Formula (XIII), w₃     is C—R₂, w₆ is C—R₁, w₂ is C—R_(b) or N and w₄ and w₅ are     independently C—R_(a) or N. -   In an aspect of the use of the compound of Formula (XIV), w₄ is     C—R₁, w₇ is C—R₂, w₂ is C—R_(b) or N and w₃ and w₅ are independently     C—R_(a) or N. -   In another aspect of the use of the compound of Formula (XIV), w₄ is     C—R₂, w₇ is C—R₁, w₂ is C—R_(b) or N and w₃ and w₅ are independently     C—R_(a) or N. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound selected from Formula (II), Formula (III), Formula     (IX), Formula (XI) or Formula (XII):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (II):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (III):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (IV):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (V):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (VI):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (VII):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (VIII):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (IX):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (X):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (XI):

-   or a form thereof. -   Another aspect of the compound of Formula (I) is the use of the     compound of Formula (XII):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (XIII):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (XIV):

-   or a form thereof. -   An aspect of the use of the compound of Formula (I), Formula (II),     Formula (III), Formula (IV), Formula (V), Formula (VI), Formula     (VII), Formula (VIII), Formula (IX), Formula (X), Formula (XI),     Formula (XII), Formula (XIII) or Formula (XIV) is the use of a     compound selected from Formula (Ia), Formula (IIa), Formula (IIIa),     Formula (IVa), Formula (Va), Formula (VIa), Formula (VIIa), Formula     (VIIIa), Formula (IXa), Formula (Xa), Formula (XIa), Formula (XIIa),     Formula (XIIIa) or Formula (XIVa), respectively:

-   or a form thereof. -   In an aspect of the use of the compound of Formula (Ia), one of w₃,     w₄, w₆ and w₇ is C—R₁ and one other of w₃, w₄, w₆ and w₇ is C—R₂,     provided that, -   when w₃ is C—R₁, then w₆ is C—R₂ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₃ is C—R₂, then w₆ is C—R₁ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₄ is C—R₁, then w₇ is C—R₂ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N; or, -   when w₄ is C—R₂, then w₇ is C—R₁ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N. -   In an aspect of the use of the compound of Formula (IIa), one of w₃,     w₄, w₆ and w₇ is C—R₁ and one other of w₃, w₄, w₆ and w₇ is C—R₂,     provided that, -   when w₃ is C—R₁, then w₆ is C—R₂ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₃ is C—R₂, then w₆ is C—R₁ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₄ is C—R₁, then w₇ is C—R₂ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N; or, -   when w₄ is C—R₂, then w₇ is C—R₁ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N. -   In an aspect of the use of the compound of Formula (IIIa), one of     w₃, w₄, w₆ and w₇ is C—R₁ and one other of w₃, w₄, w₆ and w₇ is     C—R₂, provided that, -   when w₃ is C—R₁, then w₆ is C—R₂ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₃ is C—R₂, then w₆ is C—R₁ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₄ is C—R₁, then w₇ is C—R₂ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N; or, -   when w₄ is C—R₂, then w₇ is C—R₁ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N. -   In an aspect of the use of the compound of Formula (IVa), one of w₄     and w₇ is C—R₁ and the other is C—R₂, provided that, when w₄ is     C—R₁, then w₇ is C—R₂; or, when w₄ is C—R₂, then w₇ is C—R₁. -   In an aspect of the use of the compound of Formula (Va), one of w₃     and w₆ is C—R₁ and the other is C—R₂, provided that, when w₃ is     C—R₁, then w₆ is C—R₂; or, when w₃ is C—R₂, then w₆ is C—R₁. -   In an aspect of the use of the compound of Formula (VIa), one of w₃,     w₄, w₆ and w₇ is C—R₁ and one other of w₃, w₄, w₆ and w₇ is C—R₂,     provided that, -   when w₃ is C—R₁, then w₆ is C—R₂ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₃ is C—R₂, then w₆ is C—R₁ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₄ is C—R₁, then w₇ is C—R₂ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N; or, -   when w₄ is C—R₂, then w₇ is C—R₁ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N. -   In an aspect of the use of the compound of Formula (VIIa), one of w₄     and w₇ is C—R₁ and the other is C—R₂, provided that, when w₄ is     C—R₁, then w₇ is C—R₂; or, when w₄ is C—R₂, then w₇ is C—R₁. -   In an aspect of the use of the compound of Formula (VIIIa), one of     w₃ and w₆ is C—R₁ and the other is C—R₂, provided that, when w₃ is     C—R₁, then w₆ is C—R₂; or, when w₃ is C—R₂, then w₆ is C—R₁. -   In an aspect of the use of the compound of Formula (IXa), one of w₃,     w₄, w₆ and w₇ is C—R₁ and one other of w₃, w₄, w₆ and w₇ is C—R₂,     provided that, -   when w₃ is C—R₁, then w₆ is C—R₂ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₃ is C—R₂, then w₆ is C—R₁ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₄ is C—R₁, then w₇ is C—R₂ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N; or, -   when w₄ is C—R₂, then w₇ is C—R₁ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N. -   In an aspect of the use of the compound of Formula (Xa), one of w₃     and w₆ is C—R₁ and the other is C—R₂, provided that, when w₃ is     C—R₁, then w₆ is C—R₂; or, when w₃ is C—R₂, then w₆ is C—R₁. -   In an aspect of the use of the compound of Formula (XIa), one of w₄     and w₇ is C—R₁ and the other is C—R₂, provided that, when w₄ is     C—R₁, then w₇ is C—R₂; or, when w₄ is C—R₂, then w₇ is C—R₁. -   In an aspect of the use of the compound of Formula (XIIa), one of     w₃, w₄, w₆ and w₇ is C—R₁ and one other of w₃, w₄, w₆ and w₇ is     C—R₂, provided that, -   when w₃ is C—R₁, then w₆ is C—R₂ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₃ is C—R₂, then w₆ is C—R₁ and w₄ and w₇ are independently     C—R_(a) or N; or, -   when w₄ is C—R₁, then w₇ is C—R₂ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N; or, -   when w₄ is C—R₂, then w₇ is C—R₁ and w₃ is C—R_(a) or N and w₆ is     C—R_(e) or N. -   In an aspect of the use of the compound of Formula (XIIIa), one of     w₃ and w₆ is C—R₁ and the other is C—R₂, provided that, when w₃ is     C—R₁, then w₆ is C—R₂; or, when w₃ is C—R₂, then w₆ is C—R₁. -   In an aspect of the use of the compound of Formula (XIVa), one of w₄     and w₇ is C—R₁ and the other is C—R₂, provided that, when w₄ is     C—R₁, then w₇ is C—R₂; or, when w₄ is C—R₂, then w₇ is C—R₁. -   An aspect of the use of the compound of Formula (I), Formula (II),     Formula (III), Formula (IX), Formula (XI) or Formula (XII) is the     use of the compound selected from Formula (Ia), Formula (IIa),     Formula (IIIa), Formula (IXa), Formula (XIa) or Formula (XIIa),     respectively:

-   or a form thereof. -   Another aspect of the use of the compound of Formula (I) is the use     of the compound of Formula (Ia):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (II) is the use     of the compound of Formula (IIa):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (III) is the     use of the compound of Formula (IIIa):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (IV) is the use     of the compound of Formula (IVa):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (V) is the use     of the compound of Formula (Va):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (VI) is the use     of the compound of Formula (VIa):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (VII) is the     use of the compound of Formula (VIIa):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (VIII) is the     use of the compound of Formula (VIIIa):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (IX) is the use     of the compound of Formula (IXa):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (X) is the use     of the compound of Formula (Xa):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (XI) is the use     of the compound of Formula (XIa):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (XII) is the     use of the compound of Formula (XIIa):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (XIII) is the     use of the compound of Formula (XIIIa):

-   or a form thereof. -   Another aspect of the use of the compound of Formula (XIV) is the     use of the compound of Formula (XIVa):

-   or a form thereof. -   An aspect of the use of the compound of Formula (Ia) is the use of a     compound of Formula (Ia1), Formula (Ia2), Formula (Ia3) or Formula     (Ia4):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IIa) is the use of     a compound of Formula (IIa1), Formula (IIa2), Formula (IIa3) or     Formula (IIa4):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IIIa) is the use of     a compound of Formula (IIIa1), Formula (IIIa2), Formula (IIIa3) or     Formula (IIIa4):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IVa) is the use of     a compound of Formula (IVa1) or Formula (IVa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (Va) is the use of a     compound of Formula (Va1) or Formula (Va2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (VIa) is the use of     a compound of Formula (VIa1), Formula (VIa2), Formula (VIa3) or     Formula (VIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (VIIa) is the use of     a compound of Formula (VIIa1) or Formula (VIIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (VIIIa) is the use     of a compound of Formula (VIIIa1) or Formula (VIIIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IXa) is the use of     a compound of Formula (IXa1), Formula (IXa2), Formula (IXa3) or     Formula (IXa4):

-   or a form thereof. -   An aspect of the use of the compound of Formula (Xa) is the use of a     compound of Formula (Xa1) or Formula (Xa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIa) is the use of     a compound of Formula (XIa1) or Formula (XIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIIa) is the use of     a compound of Formula (XIIa1), Formula (XIIa2), Formula (XIIa3) or     Formula (XIIa4):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIIIa) is the use     of a compound of Formula (XIIIa1) or Formula (XIIIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIVa) is the use of     a compound of Formula (XIVa1) or Formula (XIVa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (Ia) is the use of     the compound of Formula (Ia1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (Ia) is the use of     the compound of Formula (Ia2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (Ia) is the use of     the compound of Formula (Ia3):

-   or a form thereof. -   An aspect of the use of the compound of Formula (Ia) is the use of     the compound of Formula (Ia4):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IIa) is the use of     the compound of Formula (IIa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IIa) is the use of     the compound of Formula (IIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IIa) is the use of     the compound of Formula (IIa3):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IIa) is the use of     the compound of Formula (IIa4):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IIIa) is the use of     the compound of Formula (IIIa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IIIa) is the use of     the compound of Formula (IIIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IIIa) is the use of     the compound of Formula (IIIa3):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IIIa) is the use of     the compound of Formula (IIIa4):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IVa) is the use of     the compound of Formula (IVa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IVa) is the use of     the compound of Formula (IVa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (Va) is the use of     the compound of Formula (Va1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (Va) is the use of     the compound of Formula (Va2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (VIa) is the use of     the compound of Formula (VIa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (VIa) is the use of     the compound of Formula (VIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (VIa) is the use of     the compound of Formula Formula (VIa3):

-   or a form thereof. -   An aspect of the use of the compound of Formula (VIa) is the use of     the compound of Formula (VIa4):

-   or a form thereof. -   An aspect of the use of the compound of Formula (VIIa) is the use of     the compound of Formula (VIIa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (VIIa) is the use of     the compound of Formula (VIIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (VIIIa) is the use     of the compound of Formula (VIIIa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (VIIIa) is the use     of the compound of Formula (VIIIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IXa) is the use of     the compound of Formula (IXa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IXa) is the use of     the compound of Formula (IXa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IXa) is the use of     the compound of Formula (IXa3):

-   or a form thereof. -   An aspect of the use of the compound of Formula (IXa) is the use of     the compound of Formula (IXa4):

-   or a form thereof. -   An aspect of the use of the compound of Formula (Xa) is the use of     the compound of Formula (Xa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (Xa) is the use of     the compound of Formula (Xa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIa) is the use of     the compound of Formula (XIa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIa) is the use of     the compound of Formula (XIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIIa) is the use of     the compound of Formula (XIIa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIIa) is the use of     the compound of Formula (XIIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIIa) is the use of     the compound of Formula (XIIa3):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIIa) is the use of     the compound of Formula (XIIa4):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIIIa) is the use     of the compound of Formula (XIIIa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIIIa) is the use     of the compound of Formula (XIIIa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIVa) is the use of     the compound of Formula (XIVa1):

-   or a form thereof. -   An aspect of the use of the compound of Formula (XIVa) is the use of     the compound of Formula (XIVa2):

-   or a form thereof. -   An aspect of the use of the compound of Formula (I) or a form     thereof is a compound selected from the group consisting of:

wherein the form of the compound is selected from the group consisting of a salt, prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

-   An aspect of the use of the compound of Formula (I) or a form     thereof is a compound selected from the group consisting of (where     compound number (#¹) indicates that a salt form of the compound was     isolated):

Cpd Name  1 2-(4-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  2 2-(4-methoxyphenyl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  3 2-(4-methoxyphenyl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one  4 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4- one  5 7-(1,4-diazepan-1-yl)-2-(4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one  6 2-(3,4-dimethoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  7 2-(3,4-dimethoxyphenyl)-7-(3,3-dimethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  8 2-(3,4-dimethoxyphenyl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one  9 2-(3,4-dimethoxyphenyl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  10 7-(1,4-diazepan-1-yl)-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one  11 2-(3,4-dimethoxyphenyl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  12 2-(4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one  13 2-(3,4-dimethoxyphenyl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  14 2-(3,4-dimethoxyphenyl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin- 4-one  15 2-(3,4-dimethoxyphenyl)-7-(4-propylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  16 2-(4-methoxyphenyl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  17 7-(3,3-dimethylpiperazin-1-yl)-2-(4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one  18 2-(1,3-benzodioxol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  19 2-(1,3-benzodioxol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  20 2-(1,3-benzodioxol-5-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one  21 2-(1,3-benzodioxol-5-yl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin- 4-one  22 2-(3-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  23 2-(3-methoxyphenyl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  24 2-(3-methoxyphenyl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one  25 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(3-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4- one  26 7-(4-ethylpiperazin-1-yl)-2-(3-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one  27 7-(1,4-diazepan-1-yl)-2-(3-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one  28 2-(3-methoxyphenyl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  29 2-(6-methylimidazo[1,2-a]pyridin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  30 2-(3,4-dimethoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one  31 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  32 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  33 2-phenyl-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  34 7-[(3S)-3-methylpiperazin-1-yl]-2-phenyl-4H-pyrido[1,2-a]pyrimidin-4-one  35 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  36 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-(3,3-dimethylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one  37 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  38 7-(1,4-diazepan-1-yl)-2-(2,3-dihydro-1,4-benzodioxin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  39 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one  40 2-(3,4-dimethoxyphenyl)-9-fluoro-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one  41 2-(3-chlorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  42 2-(4-chlorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  43 7-(piperazin-1-yl)-2-[3-(trifluoromethyl)phenyl]-4H-pyrido[1,2-a]pyrimidin-4-one  44 7-(piperazin-1-yl)-2-[4-(trifluoromethyl)phenyl]-4H-pyrido[1,2-a]pyrimidin-4-one  45 2-(3-methylphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  46 2-(4-fluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  47 2-(4-nitrophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  48 2-(3,4-dimethoxyphenyl)-9-fluoro-7-(piperidin-4-ylamino)-4H-pyrido[1,2-a]pyrimidin-4-one  49 2-[4-(dimethylamino)phenyl]-9-fluoro-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  50 2-[4-(dimethylamino)phenyl]-9-fluoro-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  51 2-(2-fluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  52 3-(3,4-dimethoxyphenyl)-8-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  53 2-[4-(dimethylamino)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  54 2-[4-(dimethylamino)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one  55 2-(3,4-dimethylphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  56 2-(3,4-dimethylphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one  57 2-[3-(dimethylamino)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  58 2-[3-(dimethylamino)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one  59 2-[4-(difluoromethoxy)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  60 2-[4-(difluoromethoxy)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one  61 2-(3-fluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  62 2-(3-nitrophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  63 2-(4-methylphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  64 2-(2-fluoro-4,5-dimethoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  65 2-(2-fluoro-4,5-dimethoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  66 7-(3,8-diazabicyclo[3.2.1]oct-3-yl)-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4- one  67 2-[4-methoxy-3-(trifluoromethyl)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  68 2-[4-methoxy-3-(trifluoromethyl)phenyl]-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  69 2-[4-methoxy-3-(trifluoromethyl)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  70 2-(3,4-dimethoxyphenyl)-9-methoxy-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one   71¹ 2-(3,5-difluoro-4-hydroxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  72 2-(3-fluoro-4-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  73 4-[4-oxo-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-2-yl]benzonitrile  74 2-(6-methylimidazo[1,2-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  75 2-(6-methylimidazo[1,2-a]pyrazin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  76 2-[3-fluoro-5-(trifluoromethyl)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  77 2-[4-fluoro-3-(trifluoromethyl)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  78 2-[2-methoxy-3-(trifluoromethyl)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  79 2-(3,5-difluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  80 7-(piperazin-1-yl)-2-[3-(trifluoromethoxy)phenyl]-4H-pyrido[1,2-a]pyrimidin-4-one  81 2-[4-methoxy-3-(trifluoromethoxy)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one  82 2-[4-hydroxy-3-(trifluoromethoxy)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one  83 2-[4-methoxy-3-(trifluoromethoxy)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  84 2-[4-hydroxy-3-(trifluoromethoxy)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  85 2-(3,4-dimethoxyphenyl)-4-oxo-7-(piperazin-1-yl)-4H-quinolizine-1-carbonitrile  86 2-(3-fluoro-4-methoxyphenyl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one  87 2-(3-fluoro-4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one  88 2-(6-methoxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  89 2-(2,4-dimethoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  90 2-(2,4-dimethoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one  91 2-(3,4-dimethoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-quinolizin-4-one  92 2-(5-fluoropyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  93 2-(5-fluoropyridin-3-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one  94 2-(5-chloropyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  95 2-(5-chloropyridin-3-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one  96 2-(5-chloro-6-methoxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  97 2-(1H-indol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  98 2-(1H-indol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  99 2-[3-(difluoromethoxy)-4-methoxyphenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 100 2-[3-(difluoromethoxy)-4-hydroxyphenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 101 2-[3-(difluoromethoxy)-4-methoxyphenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 102 2-[3-(difluoromethoxy)-4-hydroxyphenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 103 2-(3-fluoro-4-methoxyphenyl)-7-(piperazin-1-yl)-4H-quinolizin-4-one 104 2-(3-fluoro-4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-quinolizin-4-one 105 2-(3,5-difluorophenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 106 2-(3,4-dimethoxyphenyl)-7-(piperazin-1-yl)-4H-quinolizin-4-one 107 2-(imidazo[1,2-a]pyridin-7-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 108 2-(imidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 109 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 110 2-(3-chloro-4-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 111 2-(3-chloro-4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 112 2-(3-ethoxy-4-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 113 2-(3-ethoxy-4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 114 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 115 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 116 7-(1,4-diazepan-1-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 117 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 118 2-(6,8-dimethylimidazo[1,2-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 119 2-(6,8-dimethylimidazo[1,2-a]pyrazin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 120 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 121 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 122 2-(3,4-dimethoxyphenyl)-7-(2-methylpyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 123 7-(piperazin-1-yl)-2-[2-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 124 2-(2-ethylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 125 2-(2,3-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 126 2-(3,4-dimethoxyphenyl)-7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 127 7-(4-aminopiperidin-1-yl)-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 128 7-(piperazin-1-yl)-2-(1H-pyrrolo[2,3-b]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 129 2-(1-methyl-1H-pyrrolo[2,3-b]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 130 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(1-methyl-1H-pyrrolo[2,3-b]pyridin-5-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 131 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 132 7-(1,4-diazepan-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 133 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 134 2-(2-methyl-1,3-benzoxazol-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 135 2-(2-methyl-1,3-benzothiazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 136 2-(2-methyl-1,3-benzothiazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 137 2-(2-methyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 138 2-(2-methyl-2H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 139 2-(3-fluoro-5-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 140 2-(3-fluoro-5-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 141 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 142 2-(3,4-dimethoxyphenyl)-9-methyl-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 143 2-(3,4-dimethoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 144 2-(3,4-dimethoxyphenyl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 145 2-(3-fluoro-4,5-dimethoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 146 2-(3,4-dimethoxyphenyl)-7-(4-hydroxypiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 147 2-(3,4-dimethoxyphenyl)-7-[(3S)-3-(dimethylamino)pyrrolidin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 148 2-(3,4-dimethoxyphenyl)-7-[4-(dimethylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 149 2-(4-methoxy-3-methylphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 150 3-[4-oxo-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-2-yl]benzonitrile 151 2-methoxy-5-[4-oxo-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-2-yl]benzonitrile 152 2-(3-fluoro-4-hydroxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 153 2-(4-ethoxy-3-fluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 154 2-[3-fluoro-4-(2,2,2-trifluoroethoxy)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 155 2-(2-methyl-1,3-benzoxazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 156 2-(2-methyl-1,3-benzoxazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 157 2-(3-fluoro-4-methylphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 158 2-(3-fluoro-4-methylphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 159 7-[(3S)-3-aminopyrrolidin-1-yl]-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 160 2-(3,4-dimethoxyphenyl)-9-methyl-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 161 7-(1,4-diazepan-1-yl)-2-(2-methyl-1,3-benzothiazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 162 7-[(3S)-3-methylpiperazin-1-yl]-2-(4-methyl-1,3-thiazol-2-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 163 2-(4-methyl-1,3-thiazol-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 164 2-(3,4-dimethoxyphenyl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 165 2-(3,4-dimethoxyphenyl)-7-[(3S)-3-(propan-2-ylamino)pyrrolidin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 166 2-(3-fluoro-4-methoxyphenyl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 167 2-(4-methoxy-3-nitrophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 168 2-[3-fluoro-4-(methylsulfanyl)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 169 7-(4-methyl-1,4-diazepan-1-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 170 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 171 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 172 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 173 2-(5-fluoro-6-methoxypyridin-3-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 174 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(5-fluoro-6-methoxypyridin-3-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 175 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(2-methyl-1,3-benzothiazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 176 2-(2-methyl-1,3-benzothiazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 177 2-(2-methyl-1,3-benzothiazol-5-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 178 7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(2-methyl-1,3-benzothiazol-5-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 179 2-(4-methyl-1H-imidazol-1-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 180 2-(4-methyl-1H-imidazol-1-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 181 2-(3,4-dimethoxyphenyl)-7-{[2-(methylamino)ethyl]amino}-4H-pyrido[1,2-a]pyrimidin-4-one 182 2-(5-fluoro-6-methoxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 183 2-(3,5-difluoro-4-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 184 2-(3,5-difluoro-4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 185 7-[4-(dimethylamino)piperidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2- a]pyrimidin-4-one 186 2-(3-fluoro-4-methoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 187 2-(3,4-dimethoxyphenyl)-7-(piperidin-4-ylamino)-4H-pyrido[1,2-a]pyrimidin-4-one 188 2-(3,4-dimethoxyphenyl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 189 2-(3-chloro-5-fluorophenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 190 2-(3-chloro-5-fluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 191 7-[(3S)-3-methylpiperazin-1-yl]-2-(1-methyl-1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 192 2-(1-methyl-1H-pyrazol-4-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 193 2-(2-methyl-1,3-benzoxazol-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 194 7-(3,3-dimethylpiperazin-1-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 195 7-(1,4-diazepan-1-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 196 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 197 7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 198 7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 199 2-(4,5-dimethoxypyridin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 200 7-[3-(dimethylamino)pyrrolidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-quinolizin-4-one 201 7-(4-aminopiperidin-1-yl)-2-(3-fluoro-4-methoxyphenyl)-4H-quinobzin-4-one 202 7-(4-ethylpiperazin-1-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  203¹ 7-[4-(dimethylamino)piperidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-quinolizin-4-one 204 2-(3-fluoro-4-methoxyphenyl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 205 7-[(3S)-3-(dimethylamino)pyrrolidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2- a]pyrimidin-4-one 206 7-[(3R,4R)-3-(dimethylamino)-4-hydroxypyrrobdin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H- pyrido[1,2-a]pyrimidin-4-one 207 7-(4-aminopiperidin-1-yl)-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 208 2-(3-fluoro-4-methoxyphenyl)-7-[4-(methylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin- 4-one 209 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 210 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 211 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 212 2-(3-fluoro-4-methoxyphenyl)-7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 213 2-(3-fluoro-4-methoxyphenyl)-7-[(3aR,6aS)-5-methylhexahydropyrrolo[3,4-c]pyrrol-2(1H)- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 214 2-(3,4-dimethoxyphenyl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 215 2-(4-fluoro-3-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 216 2-(4-fluoro-3-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 217 2-(3,4-difluoro-5-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 218 2-(3,4-difluoro-5-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 219 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 220 7-(3-fluoro-4-methoxyphenyl)-2-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 221 2-(2-methyl-1,3-benzothiazol-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 222 2-(3-fluoro-4-methoxyphenyl)-7-[(3S)-3-(methylamino)pyrrolidin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 223 2-(3-fluoro-4-methoxyphenyl)-7-{4-[(methylamino)methyl]piperidin-1-yl}-4H-pyrido[1,2- a]pyrimidin-4-one 224 7-[(3S)-3-aminopyrrolidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4- one 225 2-(3-fluoro-4-methoxyphenyl)-7-{[(3R)-1-methylpyrrolidin-3-yl]amino}-4H-pyrido[1,2- a]pyrimidin-4-one 226 7-{4-[(dimethylamino)methyl]piperidin-1-yl}-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2- a]pyrimidin-4-one 227 2-(6-methoxypyridin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 228 7-(piperazin-1-yl)-2-(pyridin-3-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 229 2-(5-methoxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 230 3-fluoro-5-{7-[(3S)-3-methylpiperazin-1-yl]-4-oxo-4H-pyrido[1,2-a]pyrimidin-2- yl}benzonitrile 231 3-fluoro-5-[4-oxo-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-2-yl]benzonitrile 232 2-(3-fluoro-4-methoxyphenyl)-7-[(3′S,4′S)-4′-hydroxy-1,3′-bipyrrolidin-1′-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 233 2-(3-fluoro-4-methoxyphenyl)-7-{methyl[(3R)-pyrrolidin-3-yl]amino}-4H-pyrido[1,2- a]pyrimidin-4-one 234 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 235 2-(3,4-dimethoxyphenyl)-7-[(1-methylpiperidin-4-yl)oxy]-4H-pyrido[1,2-a]pyrimidin-4-one 236 2-(3,4-dimethoxyphenyl)-7-[(3S)-pyrrolidin-3-yloxy]-4H-pyrido[1,2-a]pyrimidin-4-one 237 2-(3,4-dimethoxyphenyl)-7-(piperidin-4-yloxy)-4H-pyrido[1,2-a]pyrimidin-4-one 238 7-(1,4-diazepan-1-yl)-2-(3,4-dimethoxyphenyl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 239 2-(3-fluoro-4-methoxyphenyl)-7-{methyl[(3R)-1-methylpyrrolidin-3-yl]amino}-4H- pyrido[1,2-a]pyrimidin-4-one 240 7-[4-(dimethylamino)piperidin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 241 7-[(3S)-3-(dimethylamino)pyrrolidin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 242 7-(4-aminopiperidin-1-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 243 7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 244 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 245 2-(3,4-dimethoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-quinolizin-4-one 246 2-(3-fluoro-4-methoxyphenyl)-7-[(3aR,6aR)-1-methylhexahydropyrrolo[3,4-b]pyrrol-5(1H)- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 247 2-(3,4-dimethoxyphenyl)-9-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 248 2-(3,4-dimethoxyphenyl)-7-[1-(2-hydroxyethyl)-1,2,3,6-tetrahydropyridin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 249 2-(3,4-dimethoxyphenyl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-quinolizin-4-one 250 2-(3,4-dimethoxyphenyl)-9-methyl-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 251 2-(3,4-dimethoxyphenyl)-9-methyl-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 252 2-(3,4-dimethoxyphenyl)-9-methyl-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 253 7-(1,4-diazepan-1-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 254 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 255 7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(2-methyl-1,3-benzothiazol-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 256 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 257 2-(3,4-dimethoxyphenyl)-7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-9-methyl- 4H-pyrido[1,2-a]pyrimidin-4-one 258 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 259 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R,5S)-3,4,5-trimethylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 260 2-(3,4-dimethoxyphenyl)-9-methyl-7-[(3aR,6aS)-5-methylhexahydropyrrolo[3,4-c]pyrrol- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 261 2-(3,4-dimethoxyphenyl)-7-[4-(dimethylamino)piperidin-1-yl]-9-methyl-4H-pyrido[1,2- a]pyrimidin-4-one 262 7-[(1R,5S)-8-azabicyclo[3.2.1]oct-2-en-3-yl]-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2- a]pyrimidin-4-one 263 2-(3,4-dimethoxyphenyl)-7-(1,2,5,6-tetrahydropyridin-3-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 264 7-[(3R)-3-(dimethylamino)pyrrolidin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 265 2-(2-ethyl-1,3-benzoxazol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 266 2-(2-ethyl-1,3-benzoxazol-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin- 4-one 267 2-(2-methyl-1,3-benzoxazol-6-yl)-7-[(3aR,6aS)-5-methylhexahydropyrrolo[3,4-c]pyrrol- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 268 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 269 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 270 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 271 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 272 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 273 7-(4-aminopiperidin-1-yl)-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 274 7-[(3R)-3-(dimethylamino)pyrrolidin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 275 7-[(3S)-3-(dimethylamino)pyrrolidin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 276 2-(4-aminopiperidin-1-yl)-7-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 277 2-[(3S)-3-(dimethylamino)pyrrolidin-1-yl]-7-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2- a]pyrimidin-4-one 278 2-[(3R)-3-(dimethylamino)pyrrolidin-1-yl]-7-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2- a]pyrimidin-4-one 279 2-(3-fluoro-4-methoxyphenyl)-7-[(3aR,6aS)-5-(2-hydroxyethyl)hexahydropyrrolo[3,4- c]pyrrol-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 280 2-(3-fluoro-4-methoxyphenyl)-7-[(3aS,6aS)-1-methylhexahydropyrrolo[3,4-b]pyrrol-5(1H)- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 281 2-(3-fluoro-4-methoxyphenyl)-7-[(3aR,6aS)-5-(propan-2-yl)hexahydropyrrolo[3,4-c]pyrrol- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 282 7-[(3R)-3-(dimethylamino)pyrrolidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2- a]pyrimidin-4-one 283 7-(3,3-dimethylpiperazin-1-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 284 7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(2-methyl-1,3-benzothiazol-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 285 7-[4-(dimethylamino)piperidin-1-yl]-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 286 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(piperidin-4-yloxy)-4H-pyrido[1,2-a]pyrimidin-4-one 287 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 288 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 289 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 290 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 291 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 292 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 293 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 294 7-(3-fluoro-4-methoxyphenyl)-2-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 295 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 296 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 297 7-[4-(dimethylamino)piperidin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 298 2-[4-(dimethylamino)piperidin-1-yl]-7-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2- a]pyrimidin-4-one 299 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 300 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 301 2-(3-fluoro-4-methoxyphenyl)-7-[(4aR,7aR)-octahydro-6H-pyrrolo[3,4-b]pyridin-6-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 302 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 303 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 304 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 305 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 306 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 307 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 308 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 309 7-(4-ethylpiperazin-1-yl)-2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 310 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(4-propylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 311 7-[(3aR,6aS)-5-ethylhexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-2-(3-fluoro-4-methoxyphenyl)- 4H-pyrido[1,2-a]pyrimidin-4-one 312 2-(3-fluoro-4-methoxyphenyl)-9-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 313 2-(3-fluoro-4-methoxyphenyl)-7-[(4aR,7aR)-1-methyloctahydro-6H-pyrrolo[3,4-b]pyridin-6- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 314 2-(3,4-dimethoxyphenyl)-9-methyl-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 315 2-(3-fluoro-4-methoxyphenyl)-9-methyl-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 316 7-(3-fluoro-4-methoxyphenyl)-2-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 317 7-(3-fluoro-4-methoxyphenyl)-2-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 318 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 319 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(1-propyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 320 2-(3,4-dimethoxyphenyl)-7-[(1R,5S)-8-methyl-8-azabicyclo[3.2.1]oct-3-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 321 2-(3,4-dimethoxyphenyl)-7-[(2R)-2-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 322 2-(2-methyl-1,3-benzoxazol-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-quinolizin-4-one 323 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(4-methylpiperazin-1-yl)-4H-quinolizin-4-one 324 7-[(3S)-4-ethyl-3-methylpiperazin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-quinolizin-4- one 325 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-quinobzin-4-one 326 7-(4-aminopiperidin-1-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-quinolizin-4-one 327 2-(3-fluoro-4-methoxyphenyl)-9-methyl-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 328 7-[4-(dimethylamino)piperidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-9-methyl-4H-pyrido[1,2- a]pyrimidin-4-one 329 2-(3-fluoro-4-methoxyphenyl)-9-methyl-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 330 7-[4-(cyclopropylamino)piperidin-1-yl]-2-(3,4-dimethoxyphenyl)-9-methyl-4H-pyrido[1,2- a]pyrimidin-4-one 331 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3,4-dimethylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 332 2-(3,4-dimethoxyphenyl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-9-methyl-4H-pyrido[1,2- a]pyrimidin-4-one 333 2-(3,4-dimethoxyphenyl)-7-[(3R)-3,4-dimethylpiperazin-1-yl]-9-methyl-4H-pyrido[1,2- a]pyrimidin-4-one 334 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 335 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 336 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 337 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 338 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 339 7-[4-(dimethylamino)piperidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 340 7-(3,3-dimethylpiperazin-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 341 7-(4-cyclopropylpiperazin-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 342 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 343 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-ethyl-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 344 2-(3,4-dimethoxyphenyl)-9-methyl-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 345 2-(3,4-dimethoxyphenyl)-7-[4-(dimethylamino)piperidin-1-yl]-9-ethyl-4H-pyrido[1,2- a]pyrimidin-4-one 346 2-(3,4-dimethoxyphenyl)-7-[1-(2-hydroxyethyl)-1,2,3,6-tetrahydropyridin-4-yl]-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 347 7-[4-(dimethylamino)piperidin-1-yl]-2-(2-methyl-1,3-benzothiazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 348 7-(4-aminopiperidin-1-yl)-2-(2-methyl-1,3-benzothiazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 349 7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-2-(2-methyl-1,3-benzothiazol-5-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 350 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 351 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 352 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-propyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 353 2-(3,4-dimethoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrimido[1,2-a]pyrimidin-4- one 354 7-(1-cyclopropyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 355 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 356 7-(1-cyclobutyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 357 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(oxetan-3-yl)-1,2,3,6-tetrahydropyridin-4- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 358 2-(3,4-dimethoxyphenyl)-9-methyl-7-[4-(methylamino)piperidin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 359 2-(3,4-dimethoxyphenyl)-7-[4-(ethylamino)piperidin-1-yl]-9-methyl-4H-pyrido[1,2- a]pyrimidin-4-one 360 2-(3,4-dimethoxyphenyl)-8-methyl-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 361 2-(3,4-dimethoxyphenyl)-7-[4-(propan-2-ylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin- 4-one 362 7-(1-cyclobutyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2- a]pyrimidin-4-one 363 2-(3,4-dimethoxyphenyl)-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 364 2-(3,4-dimethoxyphenyl)-7-[1-(oxetan-3-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 365 2-(3,4-dimethoxyphenyl)-7-(1-propyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 366 2-(3,4-dimethoxyphenyl)-7-[4-(methylamino)cyclohex-1-en-1-yl]-4H-pyrido[1,2-a]pyrimidin- 4-one 367 2-(3,4-dimethoxyphenyl)-7-[4-(dimethylamino)cyclohex-1-en-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 368 2-(3,4-dimethoxyphenyl)-7-{4-[ethyl(methyl)amino]cyclohex-1-en-1-yl}-4H-pyrido[1,2- a]pyrimidin-4-one 369 2-(3,4-dimethoxyphenyl)-7-{4-[methyl(propyl)amino]cyclohex-1-en-1-yl}-4H-pyrido[1,2- a]pyrimidin-4-one 370 2-(3,4-dimethoxyphenyl)-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 371 7-(3,4-dimethoxyphenyl)-2-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 372 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 373 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[4-(propan-2-yl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 374 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[4-(propan-2-yl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 375 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 376 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 377 7-(3,4-dimethoxyphenyl)-2-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 378 2-(3,4-dimethoxyphenyl)-9-methyl-7-(1-propyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 379 7-(1-cyclobutyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(3,4-dimethoxyphenyl)-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one  380¹ 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 381 7-(4-aminopiperidin-1-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 382 7-(3-aminopyrrolidin-1-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 383 7-[(3R)-3-(dimethylamino)pyrrolidin-1-yl]-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 384 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 385 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[4-(2-methoxyethyl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 386 2-(3,4-dimethoxyphenyl)-9-methyl-7-[1-(oxetan-3-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 387 2-(3,4-dimethoxyphenyl)-9-methyl-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 388 2-(3,4-dimethoxyphenyl)-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-9-methyl-4H-pyrido[1,2- a]pyrimidin-4-one 389 2-(3,4-dimethoxyphenyl)-8-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 390 7-(1-cyclopropyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(3,4-dimethoxyphenyl)-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 391 2-(3,4-dimethoxyphenyl)-8-methyl-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 392 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 393 7-[1-(2-hydroxyethyl)-1,2,3,6-tetrahydropyridin-4-yl]-2-(2-methyl-1,3-benzothiazol-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 394 2-(2-methyl-1,3-benzothiazol-6-yl)-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 395 7-(1-cyclopropyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 396 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 397 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 398 2-(3,4-dimethoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4- one 399 7-[(1S,4S)-2,5-diazabicyclo[2.2.1]hept-2-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 400 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(1S,4S)-5-methyl-2,5-diazabicyclo[2.2.1]hept- 2-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 401 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(1S,4S)-5-ethyl-2,5-diazabicyclo[2.2.1]hept-2- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 402 2-(3,4-dimethoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4- one 403 2-(3-fluoro-4-methoxyphenyl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 404 2-(3,4-dimethoxyphenyl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 405 2-(3,4-dimethoxyphenyl)-7-[cis-4-(methylamino)cyclohexyl]-4H-pyrido[1,2-a]pyrimidin-4- one 406 2-(3,4-dimethoxyphenyl)-7-(piperidin-3-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 407 2-(3,4-dimethoxyphenyl)-9-methyl-7-[4-(propylarnino)piperidin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 408 2-(3,4-dimethoxyphenyl)-9-ethyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 409 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 410 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(piperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 411 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 412 7-(4-cyclopropylpiperazin-1-yl)-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one  413¹ 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrazino[1,2-a]pyrimidin-4-one 414 2-(3,4-dimethoxyphenyl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 415 2-(3,4-dimethoxyphenyl)-9-ethyl-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 416 2-(3,4-dimethoxyphenyl)-9-methyl-7-[4-(propan-2-ylamino)piperidin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 417 2-(3,4-dimethoxyphenyl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 418 2-(3,4-dimethoxyphenyl)-9-ethyl-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 419 2-(3,4-dimethoxyphenyl)-9-methyl-7-[4-(morpholin-4-yl)piperidin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 420 2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 421 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one hydrochloride(1:1) 422 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrazino[1,2-a]pyrimidin-4-one 423 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 424 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 425 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(pyrrolidin-1-yl)piperidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 426 7-(1,4′-bipiperidin-1′-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 427 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(4-methylpiperazin-1-yl)piperidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 428 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(morpholin-4-yl)piperidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 429 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 430 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 431 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 432 7-[4-(dimethylamino)piperidin-1-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 433 2-(3,4-dimethoxyphenyl)-7-{4-[(2-hydroxyethyl)amino]piperidin-1-yl}-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 434 2-(3,4-dimethoxyphenyl)-9-ethyl-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 435 7-[4-(diethylamino)piperidin-1-yl]-2-(3,4-dimethoxyphenyl)-9-methyl-4H-pyrido[1,2- a]pyrimidin-4-one 436 2-(3,4-dimethoxyphenyl)-9-ethyl-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 437 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-[4-(pyrrolidin-1-yl)piperidin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 438 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 439 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 440 7-(4-methylpiperazin-1-yl)-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 441 7-[(3S)-3-methylpiperazin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 442 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 443 2-(1-methyl-1H-indazol-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 444 2-[6-(dimethylamino)pyridin-3-yl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 445 7-[4-(diethylamino)piperidin-1-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 446 2-(3,4-dimethoxyphenyl)-7-{4-[(2-hydroxyethyl)(methyl)amino]piperidin-1-yl}-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 447 2-(3,4-dimethoxyphenyl)-9-ethyl-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin- 4-one 448 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 449 2-(1-methyl-1H-indazol-5-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 450 2-[6-(dimethylamino)pyridin-3-yl]-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 451 7-[4-(diethylamino)piperidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 452 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 453 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 454 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 455 2-(3,4-dimethoxyphenyl)-9-ethyl-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 456 2-(3,4-dimethoxyphenyl)-7-{4-[(2-methoxyethyl)amino]piperidin-1-yl}-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 457 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(4-methylpiperazin-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 458 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)- yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 459 7-[4-(dimethylamino)piperidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl- 4H-pyrido[1,2-a]pyrimidin-4-one 460 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 461 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 462 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 463 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 464 2-(1-methyl-1H-indazol-5-yl)-7-(1-propyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 465 2-[6-(dimethylamino)pyridin-3-yl]-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 466 7-(4-ethylpiperazin-1-yl)-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 467 7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 468 7-[4-(dimethylamino)piperidin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 469 7-[4-(2-hydroxyethyl)piperazin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 470 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-propylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 471 7-[1-(2-hydroxyethyl)-1,2,3,6-tetrahydropyridin-4-yl]-2-(1-methyl-1H-indazol-5-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 472 7-[(3R)-3-methylpiperazin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 473 2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 474 2-(2-methyl-2H-indazol-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 475 2-(1-methyl-1H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 476 2-(2-methyl-2H-indazol-5-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 477 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 478 7-(1-ethylpiperidin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 479 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]- 4H-pyrazino[1,2-a]pyrimidin-4-one 480 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 481 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1-methyl-1,2,3,6-tetrahydropyridin- 4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 482 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-9- methyl-4H-pyrido[1,2-a]pyrimidin-4-one 483 7-(1-cyclopropyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)- 9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 484 2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 485 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 486 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 487 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 488 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 489 2-(1-methyl-1H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 490 2-(1-methyl-1H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 491 7-[4-(dimethylamino)piperidin-1-yl]-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 492 7-(4-methyl-1,4-diazepan-1-yl)-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 493 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrimido[1,2- b]pyridazin-4-one 494 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 495 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-4-ethyl-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 496 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-ethyl-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 497 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-3-methyl-4-(propan-2-yl)piperazin- 1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 498 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methyl-4-(propan-2-yl)piperazin- 1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 499 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 500 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4- one 501 7-(1-ethylpiperidin-4-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrimido[1,2-b]pyridazin-4- one 502 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin- 4-one 503 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 504 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 505 2-(1-methyl-1H-indazol-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin- 4-one 506 2-(1-methyl-1H-indazol-5-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 507 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(1-methyl-1H-indazol-5-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 508 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-ethylpiperazin-1-yl)-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 509 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[(3R)-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 510 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl- 4H-pyrido[1,2-a]pyrimidin-4-one 511 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-ethyl-3-methylpiperazin-1-yl]-9- methyl-4H-pyrido[1,2-a]pyrimidin-4-one 512 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin- 4-one 513 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrimido[1,2- b]pyridazin-4-one 514 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrimido[1,2- b]pyridazin-4-one 515 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(octahydro-5H-pyrrolo[3,2-c]pyridin-5-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 516 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 517 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 518 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 519 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 520 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(4-methyl-1,4-diazepan-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 521 2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 522 2-(2-methyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 523 7-(1-ethylpiperidin-4-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 524 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrimido[1,2- b]pyridazin-4-one 525 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrimido[1,2- b]pyridazin-4-one 526 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H- pyrimido[1,2-b]pyridazin-4-one 527 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 528 7-[4-(dimethylamino)piperidin-1-yl]-2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 529 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 530 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 531 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 532 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(2-hydroxyethyl)-3-methylpiperazin-1- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 533 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-(2-methoxyethyl)-3- methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 534 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-{(3S)-4-[2-(2-hydroxyethoxy)ethyl]-3- methylpiperazin-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 535 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-cyclopropyl-3-methylpiperazin-1- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 536 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-cyclobutyl-3-methylpiperazin-1- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 537 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-(2-hydroxyethyl)-3- methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 538 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-(2-methoxyethyl)-3- methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 539 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-(2-hydroxyethyl)-3- methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 540 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-{(3S)-4-[2-(2-hydroxyethoxy)ethyl]-3- methylpiperazin-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 541 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methyl-4-(propan-2-yl)piperazin-1- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 542 7-[(3S)-4-cyclopropyl-3-methylpiperazin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6- yl)-4H-pyrido[1,2-a]pyrimidin-4-one 543 7-[(3S)-4-cyclobutyl-3-methylpiperazin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6- yl)-4H-pyrido[1,2-a]pyrimidin-4-one 544 7-(3,3-dimethylpiperazin-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 545 2-(1-methyl-1H-indazol-5-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 546 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 547 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 548 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 549 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 550 7-[4-(dimethylamino)piperidin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 551 7-[4-(diethylamino)piperidin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 552 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 553 2-(1-methyl-1H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 554 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 555 2-(2-methylimidazo[1,2-a]pyridin-7-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 556 2-(2-methylimidazo[1,2-a]pyridin-7-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 557 2-(2-methylimidazo[1,2-a]pyridin-7-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 558 7-(4-ethylpiperazin-1-yl)-2-(2-methylimidazo[1,2-a]pyridin-7-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 559 2-(2-methylimidazo[1,2-a]pyridin-7-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 560 7-(1-ethylpiperidin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-7-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 561 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[(3S)-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 562 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9- methyl-4H-pyrido[1,2-a]pyrimidin-4-one 563 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl- 4H-pyrido[1,2-a]pyrimidin-4-one 564 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[(3R,5S)-3,4,5-trimethylpiperazin-1- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 565 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]- 4H-pyrido[1,2-a]pyrimidin-4-one 566 2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 567 2-(2-methyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 568 7-(1-ethylpiperidin-4-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 569 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 570 7-{4-[(dimethylamino)methyl]piperidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 571 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(pyrrolidin-1-ylmethyl)piperidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 572 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(piperidin-1-ylmethyl)piperidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 573 2-(3,4-dimethoxyphenyl)-7-{4-[(dimethylamino)methyl]piperidin-1-yl}-4H-pyrido[1,2- a]pyrimidin-4-one 574 2-(3,4-dimethoxyphenyl)-7-[4-(pyrrolidin-1-ylmethyl)piperidin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 575 2-(3,4-dimethoxyphenyl)-7-[4-(piperidin-1-ylmethyl)piperidin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 576 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 577 7-[1-(2-hydroxyethyl)-1,2,3,6-tetrahydropyridin-4-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 578 2-(2-methyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 579 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 580 7-(1-ethylpiperidin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 581 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H- pyrazino[1,2-a]pyrimidin-4-one 582 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{4-[(2-hydroxyethyl)(methyl)amino]piperidin- 1-yl}-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 583 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[4-(propylamino)piperidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 584 7-(4-amino-4-methylpiperidin-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 585 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 586 2-(2-methyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 587 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 588 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4- one 589 2-(2-methyl-2H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 590 7-(4-ethylpiperazin-1-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 591 7-[4-(2-hydroxyethyl)piperazin-1-yl]-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 592 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 593 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 594 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H- pyrazino[1,2-a]pyrimidin-4-one 595 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H- pyrazino[1,2-a]pyrimidin-4-one 596 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(ethylamino)piperidin-1-yl]-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 597 7-{4-[bis(2-hydroxyethyl)amino]piperidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)- 9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 598 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrimido[1,2- b]pyridazin-4-one 599 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H- pyrazino[1,2-a]pyrimidin-4-one 600 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(oxetan-3-yl)piperidin-4-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 601 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 602 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methyloctahydro-5H-pyrrolo[3,2-c]pyridin- 5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 603 2-(1-methyl-1H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 604 7-(1-ethylpiperidin-4-yl)-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 605 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 606 2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 607 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 608 2-(2-methyl-2H-indazol-5-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4- one 609 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{4-[(2-hydroxyethyl)amino]piperidin-1-yl}-9- methyl-4H-pyrido[1,2-a]pyrimidin-4-one 610 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[4-(methylamino)piperidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 611 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[4-(propan-2-ylamino)piperidin-1- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 612 7-(1-ethylpiperidin-4-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 613 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 614 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 615 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 616 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 617 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 618 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-propylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 619 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(propan-2-yl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 620 7-(4-cyclopropylpiperazin-1-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 621 7-(4-cyclobutylpiperazin-1-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 622 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(oxetan-3-yl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 623 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethyloctahydro-5H-pyrrolo[3,2-c]pyridin-5- yl)-4H-pyrido[1,2-a]pyrimidin-4-one 624 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)octahydro-5H-pyrrolo[3,2- c]pyridin-5-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 625 2-(4-methoxy-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 626 2-(4-hydroxy-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 627 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrazino[1,2- a]pyrimidin-4-one 628 7-(1-cyclobutylpiperidin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 629 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 630 7-[(3R)-4-ethyl-3-methylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 631 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-3-methyl-4-propylpiperazin-1-yl]- 4H-pyrido[1,2-a]pyrimidin-4-one 632 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(2-hydroxyethyl)-3- methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 633 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 634 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(pyrrolidin-1-yl)piperidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 635 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 636 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 637 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 638 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 639 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 640 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 641 7-(1-cyclopropylpiperidin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 642 7-(1-cyclobutylpiperidin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 643 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-3-methyl-4-(propan-2-yl)piperazin- 1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 644 7-[(3R)-4-cyclopropyl-3-methylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2- yl)-4H-pyrido[1,2-a]pyrimidin-4-one 645 7-[(3R)-4-cyclobutyl-3-methylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2- yl)-4H-pyrido[1,2-a]pyrimidin-4-one 646 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-3-methyl-4-(oxetan-3-yl)piperazin-1- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 647 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 648 7-(4-cyclobutylpiperazin-1-yl)-2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 649 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-4-(2-hydroxyethyl)-3- methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 650 7-[(3R)-4-cyclobutyl-3-methylpiperazin-1-yl]-2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 651 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-(2-hydroxyethyl)-3- methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 652 7-[(3S)-4-cyclobutyl-3-methylpiperazin-1-yl]-2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 653 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 654 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 655 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 656 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 657 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 658 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 659 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 660 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-propylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 661 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 662 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-fluoroethyl)piperidin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 663 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(3-fluoropropyl)piperidin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 664 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(2-fluoroethyl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 665 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(3-fluoropropyl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 666 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(2-fluoroethyl)-3-methylpiperazin- 1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 667 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(3-fluoropropyl)-3- methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 668 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-fluoroethyl)piperidin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 669 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(3-fluoropropyl)piperidin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 670 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{(3R)-4-[2-(2-hydroxyethoxy)ethyl]-3- methylpiperazin-1-yl}-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 671 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 672 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1-methylpiperidin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 673 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(2-hydroxyethyl)-3-methylpiperazin-1- yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 674 2-[8-(hydroxymethyl)-2-methylimidazo[1,2-a]pyridin-6-yl]-7-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 675 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 676 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 677 2-[8-(hydroxymethyl)-2-methylimidazo[1,2-a]pyridin-6-yl]-7-(4-methylpiperazin-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 678 7-(4-ethylpiperazin-1-yl)-2-[8-(hydroxymethyl)-2-methylimidazo[1,2-a]pyridin-6-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 679 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 680 7-(1-cyclopropylpiperidin-4-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 681 7-(1-cyclobutylpiperidin-4-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 682 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(oxetan-3-yl)piperidin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 683 2-(4-cyclopropyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 684 2-(4-cyclopropyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 685 2-(4-cyclopropyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-ethylpiperazin-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 686 2-(4-cyclopropyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]- 4H-pyrido[1,2-a]pyrimidin-4-one 687 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-propylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 688 2-[4-(dimethylamino)-6-methylpyrazolo[1,5-a]pyrazin-2-yl]-7-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 689 2-(2-methyl-1H-benzimidazol-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 690 7-(4-ethylpiperazin-1-yl)-2-(2-methyl-1H-benzimidazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 691 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4- one 692 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 693 7-[1-(2,2-dimethyl-1,3-dioxan-5-yl)piperidin-4-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin- 2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 694 7-[1-(1,3-dihydroxypropan-2-yl)piperidin-4-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2- yl)-4H-pyrido[1,2-a]pyrimidin-4-one 695 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 696 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 697 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 698 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 699 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 700 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 701 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-4-ethyl-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 702 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 703 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-9-methyl- 4H-pyrido[1,2-a]pyrimidin-4-one 704 7-(1-cyclobutylpiperidin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 705 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 706 7-[4-(dimethylamino)-4-methylpiperidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 707 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(ethylamino)-4-methylpiperidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 708 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-methyl-4-(propylamino)piperidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 709 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{4-[(2-hydroxyethyl)amino]-4- methylpiperidin-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 710 7-(1-cyclobutylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 711 7-[1-(2-hydroxyethyl)piperidin-4-yl]-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 712 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1-propylpiperidin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 713 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 714 2-(8-cyclopropyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 715 2-(8-cyclopropyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 716 2-(8-cyclopropyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 717 2-(8-cyclopropyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R,5S)-3,5-dimethylpiperazin-1- yl]-4H-pyrido[1,2-a]pyrimidin-4-one 718 7-(1-cyclopropylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 719 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 720 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 721 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 722 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(1-methylpiperidin-4-yl)oxy]-4H-pyrido[1,2- a]pyrimidin-4-one 723 2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 724 7-(4-methylpiperazin-1-yl)-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 725 7-(4-ethylpiperazin-1-yl)-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 726 7-[4-(2-hydroxyethyl)piperazin-1-yl]-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 727 7-[(3R)-3-methylpiperazin-1-yl]-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 728 7-[(3S)-3-methylpiperazin-1-yl]-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 729 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 730 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-[(3R)-3-methyl-4-(propan-2-yl)piperazin-1-yl]- 4H-pyrido[1,2-a]pyrimidin-4-one 731 7-(4-amino-4-methylpiperidin-1-yl)-2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 732 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3S)-3-ethylpiperazin-1-yl]-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 733 2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-7-(piperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 734 7-[(3R)-3-methylpiperazin-1-yl]-2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]- 4H-pyrido[1,2-a]pyrimidin-4-one 735 7-[(3S)-3-methylpiperazin-1-yl]-2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]- 4H-pyrido[1,2-a]pyrimidin-4-one 736 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin- 6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 737 7-(4-amino-4-methylpiperidin-1-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 738 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 739 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 740 7-(3-aminoprop-1-yn-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 741 2-(2,7-dimethyl-2H-indazol-5-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 742 7-(3-aminopropyl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 743 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 744 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridin- 4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 745 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(2,2,6,6-tetramethyl-1,2,3,6- tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 746 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 747 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 748 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(1-ethyl-3-methylpyrrolo[1,2-a]pyrazin-7-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 749 7-(1,4-diazepan-1-yl)-2-(1-ethyl-3-methylpyrrolo[1,2-a]pyrazin-7-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 750 2-(2,7-dimethyl-2H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin- 4-one 751 2-(2,7-dimethyl-2H-indazol-5-yl)-7-[(3S)-3,4-dimethylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 752 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 753 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 754 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 755 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 756 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2- a]pyrimidin-4-one 757 7-[3-(dimethylamino)azetidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 758 7-[3-(diethylamino)azetidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 759 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[3-(pyrrolidin-1-yl)azetidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 760 7-(1,4-diazepan-1-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 761 7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-2-(6-methyl-4-propylpyrazolo[1,5- a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 762 2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 763 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 764 7-[(3S)-3-(aminomethyl)pyrrolidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 765 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[3-(piperidin-1-yl)azetidin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 766 2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 767 7-(2,7-diazaspiro[4.4]non-2-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 768 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 769 7-[3-(dimethylamino)propyl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 770 7-{(3S)-3-[(dimethylamino)methyl]pyrrolidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2- yl)-4H-pyrido[1,2-a]pyrimidin-4-one 771 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 772 9-methyl-2-(1-methyl-1H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 773 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 774 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1-methylpiperidin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 775 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 776 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 777 2-(1,7-dimethyl-1H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin- 4-one 778 7-{(3S)-3-[(diethylamino)methyl]pyrrolidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2- yl)-4H-pyrido[1,2-a]pyrimidin-4-one 779 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{(3S)-3-[(ethylamino)methyl]pyrrolidin-1-yl}- 4H-pyrido[1,2-a]pyrimidin-4-one 780 7-{3-[(dimethylamino)methyl]azetidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 781 7-{3-[(diethylamino)methyl]azetidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 782 2-(1-ethyl-3-methylpyrrolo[1,2-a]pyrazin-7-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 783 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[(3R)-3-methylpiperazin-1-yl]- 4H-pyrido[1,2-a]pyrimidin-4-one 784 9-methyl-2-(1-methyl-1H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 785 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9- methyl-4H-pyrido[1,2-a]pyrimidin-4-one 786 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 787 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[(3S)-3-methylpiperazin-1-yl]- 4H-pyrido[1,2-a]pyrimidin-4-one 788 7-[1-(2-hydroxyethyl)piperidin-4-yl]-9-methyl-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 789 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9- methyl-4H-pyrido[1,2-a]pyrimidin-4-one 790 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 791 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 792 7-(1-cyclobutylpiperidin-4-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H- pyrido[1,2-a]pyrimidin-4-one 793 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-9- methyl-4H-pyrido[1,2-a]pyrimidin-4-one 794 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 795 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin- 2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 796 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 797 7-[(3R)-3-(aminomethyl)pyrrolidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 798 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(2S,6S)-2,6-dimethyl-1,2,3,6- tetrahydropyridin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 799 7-{(3R)-3-[(dimethylamino)methyl]pyrrolidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2- yl)-4H-pyrido[1,2-a]pyrimidin-4-one 800 7-[(2S,6S)-2,6-dimethylpiperidin-4-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 836 2-(6-methylimidazo[1,2-a]pyridin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 837 2′-methyl-7-(piperazin-1-yl)-4H,4′H-2,7′-bipyrido[1,2-a]pyrimidine-4,4′-dione 838 2-[4-(difluoromethoxy)-3-fluorophenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 839 2-(5-fluoro-6-hydroxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 840 2-(4-hydroxy-2-methylquinazolin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 841 2-[6-(dimethylamino)pyridin-3-yl]-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 842 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-4H- pyrazino[1,2-a]pyrimidin-4-one 843 2-[4-(dimethylamino)-6-methylpyrazolo[1,5-a]pyrazin-2-yl]-7-(4-methylpiperazin-1-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 844 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[3-(trifluoromethyl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 845 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 846 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 847 tert-butyl 4-[2-(4-hydroxy-2-methoxyphenyl)-4-oxo-4H-pyrido[1,2-a]pyrimidin-7-yl]-3,6- dihydropyridine-1(2H)-carboxylate 848 tert-butyl 4-[2-(2-methoxy-4-{[(trifluoromethyl)sulfonyl]oxy}phenyl)-4-oxo-4H-pyrido[1,2- a]pyrimidin-7-yl]-3,6-dihydropyridine-1(2H)-carboxylate  849¹ 2-[4-(2-hydroxypyridin-4-yl)-2-methoxyphenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one  850¹ 2-[2-hydroxy-4-(2-hydroxypyridin-4-yl)phenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 851 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[methyl(2,2,6,6- tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 852 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[methyl(2,2,6,6-tetramethylpiperidin- 4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 853 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]- 4H-pyrido[1,2-a]pyrimidin-4-one 854 7-(piperazin-1-yl)-2-[1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  855¹ 7-(piperazin-1-yl)-2-(1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  856¹ 7-[(3S)-3-methylpiperazin-1-yl]-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 857 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 858 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H- pyrido[1,2-a]pyrimidin-4-one  859¹ 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  860¹ 2-(1,7-dimethyl-1H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one  861¹ 2-(1,7-dimethyl-1H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one  862¹ 2-(2,7-dimethyl-2H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one  863¹ 2-(2,7-dimethyl-2H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 864 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 865 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridin-4-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 866 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(2,2,6,6-tetramethylpiperidin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 867 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(2,2,6,6-tetramethylpiperidin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 868 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 869 2-(7-fluoro-2-methyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one  870¹ 9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one  871¹ 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4- one 872 7-(1-ethylpiperidin-4-yl)-2-(7-fluoro-2-methyl-2H-indazol-5-yl)-9-methyl-4H-pyrazino[1,2- a]pyrimidin-4-one 873 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-4H- pyrazino[1,2-a]pyrimidin-4-one  874¹ 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2- a]pyrimidin-4-one  875¹ 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 876 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H- pyrazino[1,2-a]pyrimidin-4-one, or 877 7-(1-ethylpiperidin-4-yl)-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-4H- pyrazino[1,2-a]pyrimidin-4-one wherein the form of the compound is selected from the group consisting of a salt, prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

-   An aspect of the compound of Formula (I) or a form thereof is a     compound selected from the group consisting of (where compound     number (#¹) indicates that a salt form of the compound was     isolated):

Cpd Name 836 2-(6-methylimidazo[1,2-a]pyridin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 837 2′-methyl-7-(piperazin-1-yl)-4H,4′H-2,7′-bipyrido[1,2-a]pyrimidine-4,4′-dione 838 2-[4-(difluoromethoxy)-3-fluorophenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 839 2-(5-fluoro-6-hydroxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 840 2-(4-hydroxy-2-methylquinazolin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 841 2-[6-(dimethylamino)pyridin-3-yl]-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 842 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-4H- pyrazino[1,2-a]pyrimidin-4-one 843 2-[4-(dimethylamino)-6-methylpyrazolo[1,5-a]pyrazin-2-yl]-7-(4-methylpiperazin-1-yl)- 4H-pyrido[1,2-a]pyrimidin-4-one 844 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[3-(trifluoromethyl)piperazin-1-yl]-4H- pyrido[1,2-a]pyrimidin-4-one 845 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one 846 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin- 4-one 847 tert-butyl 4-[2-(4-hydroxy-2-methoxyphenyl)-4-oxo-4H-pyrido[1,2-a]pyrimidin-7-yl]-3,6- dihydropyridine-1(2H)-carboxylate 848 tert-butyl 4-[2-(2-methoxy-4-{[(trifluoromethyl)sulfonyl]oxy}phenyl)-4-oxo-4H- pyrido[1,2-a]pyrimidin-7-yl]-3,6-dihydropyridine-1(2H)-carboxylate  849¹ 2-[4-(2-hydroxypyridin-4-yl)-2-methoxyphenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one  850¹ 2-[2-hydroxy-4-(2-hydroxypyridin-4-yl)phenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 851 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[methyl(2,2,6,6- tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 852 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[methyl(2,2,6,6- tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 853 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-[methyl(2,2,6,6-tetramethylpiperidin-4- yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 854 7-(piperazin-1-yl)-2-[1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl]-4H-pyrido[1,2- a]pyrimidin-4-one  855¹ 7-(piperazin-1-yl)-2-(1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one  856¹ 7-[(3S)-3-methylpiperazin-1-yl]-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 857 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 858 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H- pyrido[1,2-a]pyrimidin-4-one  859¹ 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one  860¹ 2-(1,7-dimethyl-1H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one  861¹ 2-(1,7-dimethyl-1H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one  862¹ 2-(2,7-dimethyl-2H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one  863¹ 2-(2,7-dimethyl-2H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 864 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 865 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridin- 4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 866 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(2,2,6,6-tetramethylpiperidin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 867 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(2,2,6,6-tetramethylpiperidin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one 868 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2- a]pyrimidin-4-one 869 2-(7-fluoro-2-methyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one  870¹ 9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one  871¹ 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one 872 7-(1-ethylpiperidin-4-yl)-2-(7-fluoro-2-methyl-2H-indazol-5-yl)-9-methyl-4H- pyrazino[1,2-a]pyrimidin-4-one 873 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-4H- pyrazino[1,2-a]pyrimidin-4-one  874¹ 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2- a]pyrimidin-4-one  875¹ 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-7-(piperidin-4-yl)-4H- pyrazino[1,2-a]pyrimidin-4-one 876 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H- pyrazino[1,2-a]pyrimidin-4-one, or 877 7-(1-ethylpiperidin-4-yl)-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-4H- pyrazino[1,2-a]pyrimidin-4-one wherein the form of the compound is selected from the group consisting of a salt, prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

Another aspect of the present description includes a method of use of a compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof to the subject.

Another aspect of the present description includes a use of the compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof to the subject.

Another aspect of the present description includes a use of the compound salt of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound salt of Formula (I) or a form thereof to the subject.

Another aspect of the present description includes a method of use of a compound salt of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound salt of Formula (I) thereof to the subject, wherein the compound salt is selected from the group consisting of:

Cpd Name 71 2-(3,5-difluoro-4-hydroxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:1) 203 7-[4-(dimethylamino)piperidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-quinolizin-4-one acetate (1:1) 380 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one trifluoroacetate (1:1) 413 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:2) 849 2-[4-(2-hydroxypyridin-4-yl)-2-methoxyphenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:1) 850 2-[2-hydroxy-4-(2-hydroxypyridin-4-yl)phenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one trifluoroacetate (1:1) 855 7-(piperazin-1-yl)-2-(1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:1) 856 7-[(3S)-3-methylpiperazin-1-yl]-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one hydrochloride (1:2) 859 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one hydrochloride (1:2) 860 2-(1,7-dimethyl-1H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 861 2-(1,7-dimethyl-1H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 862 2-(2,7-dimethyl-2H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 863 2-(2,7-dimethyl-2H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 870 9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one hydrochloride (1:2) 871 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one hydrochloride (1:1) 874 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2- a]pyrimidin-4-one hydrochloride (1:1), or 875 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-7-(piperidin-4-yl)-4H- pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:2) wherein the form of the compound salt is selected from the group consisting of a prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

An aspect of the compound of Formula (I) or a form thereof is a compound salt selected from the group consisting of:

Cpd Name 849 2-[4-(2-hydroxypyridin-4-yl)-2-methoxyphenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:1) 850 2-[2-hydroxy-4-(2-hydroxypyridin-4-yl)phenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one trifluoroacetate (1:1) 855 7-(piperazin-1-yl)-2-(1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:1) 856 7-[(3S)-3-methylpiperazin-1-yl]-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2- a]pyrimidin-4-one hydrochloride (1:2) 859 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4- one hydrochloride (1:2) 860 2-(1,7-dimethyl-1H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 861 2-(1,7-dimethyl-1H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 862 2-(2,7-dimethyl-2H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 863 2-(2,7-dimethyl-2H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H- pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 870 9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one hydrochloride (1:2) 871 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2- a]pyrimidin-4-one hydrochloride (1:1) 874 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2- a]pyrimidin-4-one hydrochloride (1:1), or 875 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-7-(piperidin-4-yl)-4H- pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:2) wherein the form of the compound salt is selected from the group consisting of a prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

Chemical Definitions

The chemical terms used above and throughout the description herein, unless specifically defined otherwise, shall be understood by one of ordinary skill in the art to have the following indicated meanings.

As used herein, the term “C₁₋₈alkyl” generally refers to saturated hydrocarbon radicals having from one to eight carbon atoms in a straight or branched chain configuration, including, but not limited to, methyl, ethyl, n-propyl (also referred to as propyl or propanyl), isopropyl, n-butyl (also referred to as butyl or butanyl), isobutyl, sec-butyl, tert-butyl, n-pentyl (also referred to as pentyl or pentanyl), n-hexyl (also referred to as hexyl or hexanyl), n-heptyl (also referred to as heptyl or heptanyl), n-octyl and the like. In some aspects, C₁₋₈alkyl includes, but is not limited to, C₁₋₆alkyl, C₁₋₄alkyl and the like. A C₁₋₈alkyl radical is optionally substituted with substituent species as described herein where allowed by available valences.

As used herein, the term “C₂₋₈alkenyl” generally refers to partially unsaturated hydrocarbon radicals having from two to eight carbon atoms in a straight or branched chain configuration and one or more carbon-carbon double bonds therein, including, but not limited to, ethenyl (also referred to as vinyl), allyl, propenyl and the like. In some aspects, C₂₋₈alkenyl includes, but is not limited to, C₂₋₆alkenyl, C₂₋₄alkenyl and the like. A C₂₋₈alkenyl radical is optionally substituted with substituent species as described herein where allowed by available valences.

As used herein, the term “C₂₋₈alkynyl” generally refers to partially unsaturated hydrocarbon radicals having from two to eight carbon atoms in a straight or branched chain configuration and one or more carbon-carbon triple bonds therein, including, but not limited to, ethynyl, propynyl, butynyl and the like. In some aspects, C₂₋₈alkynyl includes, but is not limited to, C₂₋₆alkynyl, C₂₋₄alkynyl and the like. A C₂₋₈alkynyl radical is optionally substituted with substituent species as described herein where allowed by available valences.

As used herein, the term “C₁₋₈alkoxy” generally refers to saturated hydrocarbon radicals having from one to eight carbon atoms in a straight or branched chain configuration of the formula: —O—C₁₋₈alkyl, including, but not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, n-hexoxy and the like. In some aspects, C₁₋₈alkoxy includes, but is not limited to, C₁₋₆alkoxy, C₁₋₄alkoxy and the like. A C₁₋₈alkoxy radical is optionally substituted with substituent species as described herein where allowed by available valences.

As used herein, the term “C₃₋₁₄cycloalkyl” generally refers to a saturated or partially unsaturated monocyclic, bicyclic or polycyclic hydrocarbon radical, including, but not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclohexenyl, cycloheptyl, cyclooctyl, 1H-indanyl, indenyl, tetrahydro-naphthalenyl and the like. In some aspects, C₃₋₁₄cycloalkyl includes, but is not limited to, C₃₋₈cycloalkyl, C₅₋₈cycloalkyl, C₃₋₁₀cycloalkyl and the like. A C₃₋₁₄cycloalkyl radical is optionally substituted with substituent species as described herein where allowed by available valences.

As used herein, the term “aryl” generally refers to a monocyclic, bicyclic or polycyclic aromatic carbon atom ring structure radical, including, but not limited to, phenyl, naphthyl, anthracenyl, fluorenyl, azulenyl, phenanthrenyl and the like. An aryl radical is optionally substituted with substituent species as described herein where allowed by available valences.

As used herein, the term “heteroaryl” generally refers to a monocyclic, bicyclic or polycyclic aromatic carbon atom ring structure radical in which one or more carbon atom ring members have been replaced, where allowed by structural stability, with one or more heteroatoms, such as an O, S or N atom, including, but not limited to, furanyl, thienyl, pyrrolyl, pyrazolyl, imidazolyl, isoxazolyl, isothiazolyl, oxazolyl, 1,3-thiazolyl, triazolyl, oxadiazolyl, thiadiazolyl, tetrazolyl, pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, indolyl, indazolyl, indolizinyl, isoindolyl, benzofuranyl, benzothienyl, benzoimidazolyl, 1,3-benzothiazolyl, 1,3-benzoxazolyl, purinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, 1,3-diazinyl, 1,2-diazinyl, 1,2-diazolyl, 1,4-diazanaphthalenyl, acridinyl, furo[3,2-b]pyridinyl, furo[3,2-c]pyridinyl, furo[2,3-c]pyridinyl, 6H-thieno[2,3-b]pyrrolyl, thieno[3,2-c]pyridinyl, thieno[2,3-d]pyrimidinyl, 1H-pyrrolo[2,3-b]pyridinyl, 1H-pyrrolo[2,3-c]pyridinyl, 1H-pyrrolo[3,2-b]pyridinyl, pyrrolo[1,2-a]pyrazinyl, pyrrolo[1,2-b]pyridazinyl, pyrazolo[1,5-a]pyridinyl, pyrazolo[1,5-a]pyrazinyl, pyrazolo[4,3-b]pyridinyl, pyrazolo[3,4-c]pyridinyl, imidazo[1,2-a]pyridinyl, 3H-imidazo[4,5-b]pyridinyl, imidazo[1,2-a]pyrimidinyl, imidazo[1,2-c]pyrimidinyl, imidazo[1,2-b]pyridazinyl, imidazo[1,2-a]pyrazinyl, imidazo[2,1-b][1,3]thiazolyl, imidazo[2,1-b][1,3,4]thiadiazolyl, [1,3]oxazolo[4,5-b]pyridinyl, [1,2,4]triazolo[1,5-a]pyridinyl, [1,2,4]triazolo[4,3-a]pyridinyl, [1,2,4]triazolo[1,5-a]pyrimidinyl, [1,2,4]triazolo[1,5-b]pyridazinyl, pyrido[1,2-a]pyrimidinyl or pyrido[1,2-a]pyrimidinone and the like. A heteroaryl radical is optionally substituted on a carbon or nitrogen atom ring member with substituent species as described herein where allowed by available valences.

In certain aspects, the nomenclature for a heteroaryl radical may differ, such as in non-limiting examples where furanyl may also be referred to as furyl, thienyl may also be referred to as thiophenyl, pyridinyl may also be referred to as pyridyl, benzothienyl may also be referred to as benzothiophenyl and 1,3-benzoxazolyl may also be referred to as 1,3-benzooxazolyl.

In certain other aspects, the term for a heteroaryl radical may also include other regioisomers, such as in non-limiting examples where the term pyrrolyl may also include 2H-pyrrolyl, 3H-pyrrolyl and the like, the term pyrazolyl may also include 1H-pyrazolyl and the like, the term imidazolyl may also include 1H-imidazolyl and the like, the term triazolyl may also include 1H-1,2,3-triazolyl and the like, the term oxadiazolyl may also include 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl and the like, the term tetrazolyl may also include 1H-tetrazolyl, 2H-tetrazolyl and the like, the term indolyl may also include 1H-indolyl and the like, the term indazolyl may also include 1H-indazolyl, 2H-indazolyl and the like, the term benzoimidazolyl may also include 1H-benzoimidazolyl and the term purinyl may also include 9H-purinyl and the like.

As used herein, the term “heterocyclyl” generally refers to a saturated or partially unsaturated monocyclic, bicyclic or polycyclic carbon atom ring structure radical in which one or more carbon atom ring members have been replaced, where allowed by structural stability, with a heteroatom, such as an O, S or N atom, including, but not limited to, oxiranyl, oxetanyl, azetidinyl, tetrahydrofuranyl, pyrrolinyl, pyrrolidinyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, isoxazolinyl, isoxazolidinyl, isothiazolinyl, isothiazolidinyl, oxazolinyl, oxazolidinyl, thiazolinyl, thiazolidinyl, triazolinyl, triazolidinyl, oxadiazolinyl, oxadiazolidinyl, thiadiazolinyl, thiadiazolidinyl, tetrazolinyl, tetrazolidinyl, pyranyl, dihydro-2H-pyranyl, thiopyranyl, 1,3-dioxanyl, 3,6-dihydropyridinyl, 1,2,5,6-tetrahydropyridinyl, 1,2,3,6-tetrahydropyridinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, 1,4-diazepanyl, 1,3-benzodioxolyl, 1,4-benzodioxanyl, 2,3-dihydro-1,4-benzodioxinyl, hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl, (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl, (3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl, hexahydropyrrolo[3,4-b]pyrrol-(2H)-yl, (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-(2H)-yl, (3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-(2H)-yl, hexahydropyrrolo[3,4-c]pyrrol-(1H)-yl, 1,3,3a,4,6,6a-hexahydropyrrolo[3,4-c]pyrrolyl, (3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-(1H)-yl, (3aR,6aR)-hexahydropyrrolo[3,4-c]pyrrol-(1H)-yl, octahydro-5H-pyrrolo[3,2-c]pyridinyl, octahydro-6H-pyrrolo[3,4-b]pyridinyl, (4aR,7aR)-octahydro-6H-pyrrolo[3,4-b]pyridinyl, (4aS,7aS)-octahydro-6H-pyrrolo[3,4-b]pyridinyl, hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl, (7R,8aS)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl, (8aS)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl, (8aR)-hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl, (8aS)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazinyl, (8aR)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazinyl, (8aS)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazinyl, (8aR)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazinyl, (8aS)-octahydropyrrolo[1,2-a]pyrazin-(1H)-yl, (8aR)-octahydropyrrolo[1,2-a]pyrazin-(1H)-yl, hexahydropyrrolo[1,2-a]pyrazin-(2H)-one, octahydro-2H-pyrido[1,2-a]pyrazinyl, (3aR,4aR,7aS)-hexahydro-1H-cyclobuta[1,2-c:1,4-c′]dipyrrol-(3H)-yl, 3-azabicyclo[3.1.0]hexyl, (1R,5S)-3-azabicyclo[3.1.0]hexyl, 8-azabicyclo[3.2.1]octyl, (1R,5S)-8-azabicyclo[3.2.1]octyl, 8-azabicyclo[3.2.1]oct-2-enyl, (1R,5S)-8-azabicyclo[3.2.1]oct-2-enyl, 9-azabicyclo[3.3.1]nonyl, (1R,5S)-9-azabicyclo[3.3.1]nonyl, 2,5-diazabicyclo[2.2.1]heptyl, (1S,4S)-2,5-diazabicyclo[2.2.1]heptyl, 2,5-diazabicyclo[2.2.2]octyl, 3,6-diazabicyclo[3.2.0]heptyl, 3,8-diazabicyclo[3.2.1]octyl, (1R,5S)-3,8-diazabicyclo[3.2.1]octyl, 1,4-diazabicyclo[3.2.2]nonyl, azaspiro[3.3]heptyl, 2,6-diazaspiro[3.3]heptyl, 4,7-diazaspiro[2.5]octyl, 2,6-diazaspiro[3.4]octyl, 2,7-diazaspiro[3.5]nonyl, 5,8-diazaspiro[3.5]nonyl, 2,7-diazaspiro[4.4]nonyl, 6,9-diazaspiro[4.5]decyl and the like. A heterocyclyl radical is optionally substituted on a carbon or nitrogen atom ring member with substituent species as described herein where allowed by available valences.

In certain aspects, the nomenclature for a heterocyclyl radical may differ, such as in non-limiting examples where 1,3-benzodioxolyl may also be referred to as benzo[d][1,3]dioxolyl; 2,3-dihydro-1,4-benzodioxinyl may also be referred to as 2,3-dihydrobenzo[b][1,4]dioxinyl; 2,6-diazaspiro[3.3]heptyl may also be referred to as 2,6-diazaspiro[3.3]heptanyl; 4,7-diazaspiro[2.5]octyl may also be referred to as 4,7-diazaspiro[2.5]octanyl; 2,7-diazaspiro[3.5]nonyl may also be referred to as 2,7-diazaspiro[3.5]nonanyl; and, the like.

As used herein, the term “C₁₋₈alkoxy-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-O—C₁₋₈alkyl.

As used herein, the term “C₁₋₈alkoxy-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-O—C₁₋₈alkyl.

As used herein, the term “(C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino” refers to a radical of the formula: —N(C₁₋₈alkyl-O—C₁₋₈alkyl)₂.

As used herein, the term “C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-NH—C₁₋₈alkyl-O—C₁₋₈alkyl.

As used herein, the term “(C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-N(C₁₋₈alkyl-O—C₁₋₈alkyl)₂.

As used herein, the term “(C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-N(C₁₋₈alkyl)(C₁₋₈alkyl-O—C₁₋₈alkyl).

As used herein, the term “C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-NH—C₁₋₈alkyl-O—C₁₋₈alkyl.

As used herein, the term “(C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N(C₁₋₈alkyl-O—C₁₋₈alkyl)₂.

As used herein, the term “(C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N(C₁₋₈alkyl)(C₁₋₈alkyl-O—C₁₋₈alkyl).

As used herein, the term “C₁₋₈alkoxy-carbonyl” refers to a radical of the formula: —C(O)—O—C₁₋₈alkyl.

As used herein, the term “C₁₋₈alkoxy-carbonyl-C₂₋₈alkenyl” refers to a radical of the formula: —C₂₋₈alkenyl-C(O)—O—C₁₋₈alkyl.

As used herein, the term “C₁₋₈alkoxy-carbonyl-amino” refers to a radical of the formula: —NH—C(O)—O—C₁₋₈alkyl.

As used herein, the term “C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl.

As used herein, the term “(C₁₋₈alkyl)₂-amino” refers to a radical of the formula: —N(C₁₋₈alkyl)₂.

As used herein, the term “C₁₋₈alkyl-amino-C₂₋₈alkenyl” refers to a radical of the formula: —C₂₋₈alkenyl-NH—C₁₋₈alkyl.

As used herein, the term “(C₁₋₈alkyl)₂-amino-C₂₋₈alkenyl” refers to a radical of the formula: —C₂₋₈alkenyl-N(C₁₋₈alkyl)₂.

As used herein, the term “C₁₋₈alkyl-amino-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-NH—C₁₋₈alkyl.

As used herein, the term “(C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-N(C₁₋₈alkyl)₂.

As used herein, the term “C₁₋₈alkyl-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-NH—C₁₋₈alkyl.

As used herein, the term “(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N(C₁₋₈alkyl)₂.

As used herein, the term “C₁₋₈alkyl-amino-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-NH—C₁₋₈alkyl.

As used herein, the term “(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-N(C₁₋₈alkyl)₂.

As used herein, the term “(C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino” refers to a radical of the formula: —N(C₁₋₈alkyl-NH—C₁₋₈alkyl)₂.

As used herein, the term “[(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl]₂-amino” refers to a radical of the formula: —N[C₁₋₈alkyl-N(C₁₋₈alkyl)_(2]2.)

As used herein, the term “(C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)(C₁₋₈alkyl-NH—C₁₋₈alkyl).

As used herein, the term “[(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)[C₁₋₈alkyl-N(C₁₋₈alkyl)₂].

As used herein, the term “C₁₋₈alkyl-amino-C₂₋₈alkynyl” refers to a radical of the formula: —C₂₋₈alkynyl-NH—C₁₋₈alkyl.

As used herein, the term “(C₁₋₈alkyl)₂-amino-C₂₋₈alkynyl” refers to a radical of the formula: —C₂₋₈alkynyl-N(C₁₋₈alkyl)₂.

As used herein, the term “C₁₋₈alkyl-carbonyl” refers to a radical of the formula: —C(O)—C₁₋₈alkyl.

As used herein, the term “C₁₋₈alkyl-carbonyl-amino” refers to a radical of the formula: —NH—C(O)—C₁₋₈alkyl.

As used herein, the term “C₁₋₈alkyl-thio” refers to a radical of the formula: —S—C₁₋₈alkyl.

As used herein, the term “amino-C₂₋₈alkenyl” refers to a radical of the formula: —C₂₋₈alkenyl-NH₂.

As used herein, the term “amino-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-NH₂.

As used herein, the term “amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-NH₂.

As used herein, the term “amino-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-NH₂.

As used herein, the term “(amino-C₁₋₈alkyl)₂-amino” refers to a radical of the formula: —N(C₁₋₈alkyl-NH₂)₂.

As used herein, the term “(amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)(C₁₋₈alkyl-NH₂).

As used herein, the term “amino-C₂₋₈alkynyl” refers to a radical of the formula: —C₂₋₈alkynyl-NH₂.

As used herein, the term “aryl-C₁₋₈alkoxy-carbonyl” refers to a radical of the formula: —C(O)—O—C₁₋₈alkyl-aryl.

As used herein, the term “aryl-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-aryl.

As used herein, the term “aryl-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-aryl.

As used herein, the term “(aryl-C₁₋₈alkyl)₂-amino” refers to a radical of the formula: —N(C₁₋₈alkyl-aryl)₂.

As used herein, the term “(aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)(C₁₋₈alkyl-aryl).

As used herein, the term “aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-NH—C₁₋₈alkyl-aryl.

As used herein, the term “(aryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N(C₁₋₈alkyl-aryl)₂.

As used herein, the term “(aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N(C₁₋₈alkyl)(C₁₋₈alkyl-aryl).

As used herein, the term “aryl-amino” refers to a radical of the formula: —NH-aryl.

As used herein, the term “aryl-amino-carbonyl” refers to a radical of the formula: —C(O)—NH-aryl.

As used herein, the term “aryl-sulfonyloxy-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-O—SO₂-aryl.

As used herein, the term “benzoxy-carbonyl” refers to a radical of the formula: —C(O)—O—CH₂-phenyl.

As used herein, the term “C₃₋₁₄cycloalkyl-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-C₃₋₁₄cycloalkyl.

As used herein, the term “C₃₋₁₄cycloalkyl-amino” refers to a radical of the formula: —NH—C₃₋₁₄cycloalkyl.

As used herein, the term “C₃₋₁₄cycloalkyl-oxy” refers to a radical of the formula: —O—C₃₋₁₄cycloalkyl.

As used herein, the term “halo” or “halogen” generally refers to a halogen atom radical, including fluoro, chloro, bromo and iodo.

As used herein, the term “halo-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-halo, wherein C₁₋₈alkyl is partially or completely substituted with one or more halogen atoms where allowed by available valences.

As used herein, the term “halo-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-halo, wherein C₁₋₈alkyl is partially or completely substituted with one or more halogen atoms where allowed by available valences.

As used herein, the term “halo-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-halo.

As used herein, the term “(halo-C₁₋₈alkyl)(C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)(C₁₋₈alkyl-halo).

As used herein, the term “(halo-C₁₋₈alkyl)₂-amino” refers to a radical of the formula: —N(C₁₋₈alkyl-halo)₂.

As used herein, the term “heteroaryl-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-heteroaryl.

As used herein, the term “heteroaryl-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-heteroaryl.

As used herein, the term “heteroaryl-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-heteroaryl.

As used herein, the term “(heteroaryl-C₁₋₈alkyl)₂-amino” refers to a radical of the formula: —N(C₁₋₈alkyl-heteroaryl)₂.

As used herein, the term “(heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)(C₁₋₈alkyl-heteroaryl).

As used herein, the term “heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-NH—C₁₋₈alkyl-heteroaryl.

As used herein, the term “(heteroaryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N(C₁₋₈alkyl-heteroaryl)₂.

As used herein, the term “(heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N(C₁₋₈alkyl)(C₁₋₈alkyl-heteroaryl).

As used herein, the term “heteroaryl-amino” refers to a radical of the formula: —NH-heteroaryl.

As used herein, the term “heterocyclyl-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-heterocyclyl.

As used herein, the term “heterocyclyl-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-heterocyclyl.

As used herein, the term “heterocyclyl-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-heterocyclyl.

As used herein, the term “(heterocyclyl-C₁₋₈alkyl)₂-amino” refers to a radical of the formula: —N(C₁₋₈alkyl-heterocyclyl)₂.

As used herein, the term “(heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)(C₁₋₈alkyl-heterocyclyl).

As used herein, the term “heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-NH—C₁₋₈alkyl-heterocyclyl.

As used herein, the term “(heterocyclyl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N(C₁₋₈alkyl-heterocyclyl)₂.

As used herein, the term “(heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N(C₁₋₈alkyl)(C₁₋₈alkyl-heterocyclyl).

As used herein, the term “heterocyclyl-amino” refers to a radical of the formula: —NH-heterocyclyl.

As used herein, the term “(heterocyclyl)(C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)(heterocyclyl).

As used herein, the term “heterocyclyl-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-NH-heterocyclyl.

As used herein, the term “heterocyclyl-carbonyl” refers to a radical of the formula: —C(O)-heterocyclyl.

As used herein, the term “heterocyclyl-carbonyl-oxy” refers to a radical of the formula: —O—C(O)-heterocyclyl.

As used herein, the term “heterocyclyl-oxy” refers to a radical of the formula: —O-heterocyclyl.

As used herein, the term “hydroxy” refers to a radical of the formula: —OH.

As used herein, the term “hydroxy-C₁₋₈alkoxy-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-O—C₁₋₈alkyl-OH.

As used herein, the term “hydroxy-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-OH, wherein C₁₋₈alkyl is partially or completely substituted with one or more hydroxy radicals where allowed by available valences.

As used herein, the term “hydroxy-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-OH.

As used herein, the term “(hydroxy-C₁₋₈alkyl)₂-amino” refers to a radical of the formula: —N(C₁₋₈alkyl-OH)₂.

As used herein, the term “(hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)(C₁₋₈alkyl-OH).

As used herein, the term “hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N-CalkylC₁₋₈alkyl-OH.

As used herein, the term “(hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N(C₁₋₈alkyl-OH)₂.

As used herein, the term “(hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl” refers to a radical of the formula: —C₁₋₈alkyl-N(C₁₋₈alkyl)(C₁₋₈alkyl-OH).

As used herein, the term “hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-NH—C₁₋₈alkyl-OH.

As used herein, the term “(hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-N(C₁₋₈alkyl-OH)₂.

As used herein, the term “(hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy” refers to a radical of the formula: —O—C₁₋₈alkyl-N(C₁₋₈alkyl)(C₁₋₈alkyl-OH).

As used herein, the term “hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-NH—C₁₋₈alkyl-OH.

As used herein, the term “(hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino” refers to a radical of the formula: —N(C₁₋₈alkyl-NH—C₁₋₈alkyl-OH)₂.

As used herein, the term “(hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-N(C₁₋₈alkyl-OH)₂.

As used herein, the term “(hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)(C₁₋₈alkyl-NH—C₁₋₈alkyl-OH).

As used herein, the term “[(hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)[C₁₋₈alkyl-N(C₁₋₈alkyl-OH)₂].

As used herein, the term “(hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl-amino” refers to a radical of the formula: —NH—C₁₋₈alkyl-N(C₁₋₈alkyl,C₁₋₈alkyl-OH).

As used herein, the term “[(hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl](C₁₋₈alkyl)amino” refers to a radical of the formula: —N(C₁₋₈alkyl)[C₁₋₈alkyl-N(C₁₋₈alkyl)(C₁₋₈alkyl-OH)].

As used herein, the term “substituent” means positional variables on the atoms of a core molecule that are substituted at a designated atom position, replacing one or more hydrogens on the designated atom, provided that the designated atom's normal valency is not exceeded, and that the substitution results in a stable compound. Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds. A person of ordinary skill in the art should note that any carbon as well as heteroatom with valences that appear to be unsatisfied as described or shown herein is assumed to have a sufficient number of hydrogen atom(s) to satisfy the valences described or shown. In certain instances one or more substituents having a double bond (e.g., “oxo” or “═O”) as the point of attachment may be described, shown or listed herein within a substituent group, wherein the structure may only show a single bond as the point of attachment to the core structure of Formula (I). A person of ordinary skill in the art would understand that, while only a single bond is shown, a double bond is intended for those substituents.

As used herein, the term “and the like,” with reference to the definitions of chemical terms provided herein, means that variations in chemical structures that could be expected by one skilled in the art include, without limitation, isomers (including chain, branching or positional structural isomers), hydration of ring systems (including saturation or partial unsaturation of monocyclic, bicyclic or polycyclic ring structures) and all other variations where allowed by available valences which result in a stable compound.

For the purposes of this description, where one or more substituent variables for a compound of Formula (I) or a form thereof encompass functionalities incorporated into a compound of Formula (I), each functionality appearing at any location within the disclosed compound may be independently selected, and as appropriate, independently and/or optionally substituted.

As used herein, the terms “independently selected,” or “each selected” refer to functional variables in a substituent list that may occur more than once on the structure of Formula (I), the pattern of substitution at each occurrence is independent of the pattern at any other occurrence.

Further, the use of a generic substituent variable on any formula or structure for a compound described herein is understood to include the replacement of the generic substituent with species substituents that are included within the particular genus, e.g., aryl may be replaced with phenyl or naphthalenyl and the like, and that the resulting compound is to be included within the scope of the compounds described herein.

As used herein, the terms “each instance of” or “in each instance, when present,” when used preceding a phrase such as “ . . . C₃₋₁₄cycloalkyl, C₃₋₁₄cycloalkyl-C₁₋₄alkyl, aryl, aryl-C₁₋₄alkyl, heteroaryl, heteroaryl-C₁₋₄alkyl, heterocyclyl and heterocyclyl-C₁₋₄alkyl,” are intended to refer to the C₃₋₁₄cycloalkyl, aryl, heteroaryl and heterocyclyl ring systems when each are present either alone or as a substituent.

As used herein, the term “optionally substituted” means optional substitution with the specified substituent variables, groups, radicals or moieties.

Compound Forms

As used herein, the term “form” means a compound of Formula (I) having a form selected from the group consisting of a free acid, free base, prodrug, salt, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.

In certain aspects described herein, the form of the compound of Formula (I) is a free acid, free base or salt thereof.

In certain aspects described herein, the form of the compound of Formula (I) is a salt thereof.

In certain aspects described herein, the form of the compound of Formula (I) is an isotopologue thereof.

In certain aspects described herein, the form of the compound of Formula (I) is a stereoisomer, racemate, enantiomer or diastereomer thereof.

In certain aspects described herein, the form of the compound of Formula (I) is a tautomer thereof.

In certain aspects described herein, the form of the compound of Formula (I) is a pharmaceutically acceptable form.

In certain aspects described herein, the compound of Formula (I) or a form thereof is isolated for use.

As used herein, the term “isolated” means the physical state of a compound of Formula (I) or a form thereof after being isolated and/or purified from a synthetic process (e.g., from a reaction mixture) or natural source or combination thereof according to an isolation or purification process or processes described herein or which are well known to the skilled artisan (e.g., chromatography, recrystallization and the like) in sufficient purity to be characterized by standard analytical techniques described herein or well known to the skilled artisan.

As used herein, the term “protected” means that a functional group in a compound of Formula (I) or a form thereof is in a form modified to preclude undesired side reactions at the protected site when the compound is subjected to a reaction. Suitable protecting groups will be recognized by those with ordinary skill in the art as well as by reference to standard textbooks such as, for example, T. W. Greene et al, Protective Groups in organic Synthesis (1991), Wiley, New York. Such functional groups include hydroxy, phenol, amino and carboxylic acid. Suitable protecting groups for hydroxy or phenol include trialkylsilyl or diarylalkylsilyl (e.g., t-butyldimethylsilyl, t-butyldiphenylsilyl or trimethylsilyl), tetrahydropyranyl, benzyl, substituted benzyl, methyl, methoxymethanol, and the like. Suitable protecting groups for amino, amidino and guanidino include t-butoxycarbonyl, benzyloxycarbonyl, and the like. Suitable protecting groups for carboxylic acid include alkyl, aryl or arylalkyl esters. In certain instances, the protecting group may also be a polymer resin, such as a Wang resin or a 2-chlorotrityl-chloride resin. Protecting groups may be added or removed in accordance with standard techniques, which are well-known to those skilled in the art and as described herein. It will also be appreciated by those skilled in the art, although such protected derivatives of compounds described herein may not possess pharmacological activity as such, they may be administered to a subject and thereafter metabolized in the body to form compounds described herein which are pharmacologically active. Such derivatives may therefore be described as “prodrugs”. All prodrugs of compounds described herein are included within the scope of the use described herein.

As used herein, the term “prodrug” means a form of an instant compound (e.g., a drug precursor) that is transformed in vivo to yield an active compound of Formula (I) or a form thereof. The transformation may occur by various mechanisms (e.g., by metabolic and/or non-metabolic chemical processes), such as, for example, by hydrolysis and/or metabolism in blood, liver and/or other organs and tissues. A discussion of the use of prodrugs is provided by T. Higuchi and W. Stella, “Pro-drugs as Novel Delivery Systems,” Vol. 14 of the A.C.S. Symposium Series, and in Bioreversible Carriers in Drug Design, ed. Edward B. Roche, American Pharmaceutical Association and Pergamon Press, 1987.

In one example, when a compound of Formula (I) or a form thereof contains a carboxylic acid functional group, a prodrug can comprise an ester formed by the replacement of the hydrogen atom of the acid group with a functional group such as alkyl and the like. In another example, when a compound of Formula (I) or a form thereof contains a hydroxyl functional group, a prodrug form can be prepared by replacing the hydrogen atom of the hydroxyl with another functional group such as alkyl, alkylcarbonyl or a phosphonate ester and the like. In another example, when a compound of Formula (I) or a form thereof contains an amine functional group, a prodrug form can be prepared by replacing one or more amine hydrogen atoms with a functional group such as alkyl or substituted carbonyl. Pharmaceutically acceptable prodrugs of compounds of Formula (I) or a form thereof include those compounds substituted with one or more of the following groups: carboxylic acid esters, sulfonate esters, amino acid esters, phosphonate esters and mono-, di- or triphosphate esters or alkyl substituents, where appropriate. As described herein, it is understood by a person of ordinary skill in the art that one or more of such substituents may be used to provide a compound of Formula (I) or a form thereof as a prodrug.

One or more compounds described herein may exist in unsolvated as well as solvated forms with pharmaceutically acceptable solvents such as water, ethanol, and the like, and the description herein is intended to embrace both solvated and unsolvated forms.

As used herein, the term “solvate” means a physical association of a compound described herein with one or more solvent molecules. This physical association involves varying degrees of ionic and covalent bonding, including hydrogen bonding. In certain instances the solvate will be capable of isolation, for example when one or more solvent molecules are incorporated in the crystal lattice of the crystalline solid. As used herein, “solvate” encompasses both solution-phase and isolatable solvates. Non-limiting examples of suitable solvates include ethanolates, methanolates, and the like.

As used herein, the term “hydrate” means a solvate wherein the solvent molecule is water.

The compounds of Formula (I) can form salts, which are intended to be included within the scope of this description. Reference to a compound of Formula (I) or a form thereof herein is understood to include reference to salt forms thereof, unless otherwise indicated. The term “salt(s)”, as employed herein, denotes acidic salts formed with inorganic and/or organic acids, as well as basic salts formed with inorganic and/or organic bases. In addition, when a compound of Formula (I) or a form thereof contains both a basic moiety, such as, without limitation an amine moiety, and an acidic moiety, such as, but not limited to a carboxylic acid, zwitterions (“inner salts”) may be formed and are included within the term “salt(s)” as used herein.

The term “pharmaceutically acceptable salt(s)”, as used herein, means those salts of compounds described herein that are safe and effective (i.e., non-toxic, physiologically acceptable) for use in mammals and that possess biological activity, although other salts are also useful. Salts of the compounds of the Formula (I) may be formed, for example, by reacting a compound of Formula (I) or a form thereof with an amount of acid or base, such as an equivalent amount, in a medium such as one in which the salt precipitates or in an aqueous medium followed by lyophilization.

Pharmaceutically acceptable salts include one or more salts of acidic or basic groups present in compounds described herein. Aspects of acid addition salts include, and are not limited to, acetate, ascorbate, benzoate, benzenesulfonate, bisulfate, bitartrate, borate, bromide, butyrate, chloride, citrate, camphorate, camphorsulfonate, ethanesulfonate, formate, fumarate, gentisinate, gluconate, glucaronate, glutamate, iodide, isonicotinate, lactate, maleate, methanesulfonate, naphthalenesulfonate, nitrate, oxalate, pamoate, pantothenate, phosphate, propionate, saccharate, salicylate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate (also known as tosylate), trifluoroacetate salts and the like. Certain aspects of acid addition salts include chloride, dichloride, trichloride, bromide, acetate, formate or trifluoroacetate salts.

Additionally, acids which are generally considered suitable for the formation of pharmaceutically useful salts from basic pharmaceutical compounds are discussed, for example, by P. Stahl et al, Camille G. (eds.) Handbook of Pharmaceutical Salts. Properties, Selection and Use. (2002) Zurich: Wiley-VCH; S. Berge et al, Journal of Pharmaceutical Sciences (1977) 66(1) 1-19; P. Gould, International J. of Pharmaceutics (1986) 33, 201-217; Anderson et al, The Practice of Medicinal Chemistry (1996), Academic Press, New York; and in The Orange Book (Food & Drug Administration, Washington, D.C. on their website). These disclosures are incorporated herein by reference thereto.

Suitable basic salts include, but are not limited to, aluminum, ammonium, calcium, lithium, magnesium, potassium, sodium and zinc salts.

All such acid salts and base salts are intended to be included within the scope of pharmaceutically acceptable salts as described herein. In addition, all such acid and base salts are considered equivalent to the free forms of the corresponding compounds for purposes of this description.

Compounds of Formula (I) and forms thereof, may further exist in a tautomeric form. All such tautomeric forms are contemplated and intended to be included within the scope of the compounds of Formula (I) or a form thereof as described herein.

The compounds of Formula (I) or a form thereof may contain asymmetric or chiral centers, and, therefore, exist in different stereoisomeric forms. The present description is intended to include all stereoisomeric forms of the compounds of Formula (I) as well as mixtures thereof, including racemic mixtures.

The compounds described herein may include one or more chiral centers, and as such may exist as racemic mixtures (R/S) or as substantially pure enantiomers and diastereomers. The compounds may also exist as substantially pure (R) or (S) enantiomers (when one chiral center is present). In one aspect, the compounds described herein are (S) isomers and may exist as enantiomerically pure compositions substantially comprising only the (S) isomer. In another aspect, the compounds described herein are (R) isomers and may exist as enantiomerically pure compositions substantially comprising only the (R) isomer. As one of skill in the art will recognize, when more than one chiral center is present, the compounds described herein may also exist as a (R,R), (R,S), (S,R) or (S,S) isomer, as defined by IUPAC Nomenclature Recommendations.

As used herein, the term “substantially pure” refers to compounds consisting substantially of a single isomer in an amount greater than or equal to 90%, in an amount greater than or equal to 92%, in an amount greater than or equal to 95%, in an amount greater than or equal to 98%, in an amount greater than or equal to 99%, or in an amount equal to 100% of the single isomer.

In one aspect of the description, a compound of Formula (I) or a form thereof is a substantially pure (S) enantiomer form present in an amount greater than or equal to 90%, in an amount greater than or equal to 92%, in an amount greater than or equal to 95%, in an amount greater than or equal to 98%, in an amount greater than or equal to 99%, or in an amount equal to 100%.

In one aspect of the description, a compound of Formula (I) or a form thereof is a substantially pure (R) enantiomer form present in an amount greater than or equal to 90%, in an amount greater than or equal to 92%, in an amount greater than or equal to 95%, in an amount greater than or equal to 98%, in an amount greater than or equal to 99%, or in an amount equal to 100%.

As used herein, a “racemate” is any mixture of isometric forms that are not “enantiomerically pure”, including mixtures such as, without limitation, in a ratio of about 50/50, about 60/40, about 70/30, or about 80/20.

In addition, the present description embraces all geometric and positional isomers. For example, if a compound of Formula (I) or a form thereof incorporates a double bond or a fused ring, both the cis- and trans-forms, as well as mixtures, are embraced within the scope of the description. Diastereomeric mixtures can be separated into their individual diastereomers on the basis of their physical chemical differences by methods well known to those skilled in the art, such as, for example, by chromatography and/or fractional crystallization. Enantiomers can be separated by use of chiral HPLC column or other chromatographic methods known to those skilled in the art. Enantiomers can also be separated by converting the enantiomeric mixture into a diastereomeric mixture by reaction with an appropriate optically active compound (e.g., chiral auxiliary such as a chiral alcohol or Mosher's acid chloride), separating the diastereomers and converting (e.g., hydrolyzing) the individual diastereomers to the corresponding pure enantiomers. Also, some of the compounds of Formula (I) may be atropisomers (e.g., substituted biaryls) and are considered as part of this description.

All stereoisomers (for example, geometric isomers, optical isomers and the like) of the present compounds (including those of the salts, solvates, esters and prodrugs of the compounds as well as the salts, solvates and esters of the prodrugs), such as those which may exist due to asymmetric carbons on various substituents, including enantiomeric forms (which may exist even in the absence of asymmetric carbons), rotameric forms, atropisomers, and diastereomeric forms, are contemplated within the scope of this description, as are positional isomers (such as, for example, 4-pyridyl and 3-pyridyl). Individual stereoisomers of the compounds described herein may, for example, be substantially free of other isomers, or may be present in a racemic mixture, as described supra.

The use of the terms “salt”, “solvate”, “ester”, “prodrug” and the like, is intended to equally apply to the salt, solvate, ester and prodrug of enantiomers, stereoisomers, rotamers, tautomers, positional isomers, racemates or isotopologues of the instant compounds.

The term “isotopologue” refers to isotopically-enriched compounds described herein which are identical to those recited herein, but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds described herein include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, fluorine and chlorine, such as ²H, ³H, ¹³C, ¹⁴C, ¹⁵N, ¹⁸O, ¹⁷O, ³¹P, ³²P, ³⁵S, ¹⁸F, ³⁵Cl and ³⁶Cl, respectively, each of which are also within the scope of this description.

Certain isotopically-enriched compounds described herein (e.g., those labeled with ³H and ¹⁴C) are useful in compound and/or substrate tissue distribution assays. Tritiated (i.e., ³H) and carbon-14 (i.e., ¹⁴C) isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with heavier isotopes such as deuterium (i.e., ²H) may afford certain therapeutic advantages resulting from greater metabolic stability (e.g., increased in vivo half-life or reduced dosage requirements) and hence may be preferred in some circumstances.

Polymorphic crystalline and amorphous forms of the compounds of Formula (I) and of the salts, solvates, hydrates, esters and prodrugs of the compounds of Formula (I) are further intended to be included in the present description.

Compound Uses

The present description relates to a method or use of a compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound or a form thereof to the subject.

The present description also relates to a method of use of the compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof.

The present description further relates to use of the compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof.

The present description further relates to use of the compound of Formula (I) or a form thereof having activity toward HD.

The present description further relates to use of the compound of Formula (I) or a form thereof in a combination therapy to provide additive or synergistic activity, thus enabling the development of a combination product for treating or ameliorating HD.

In addition to monotherapeutic use, the instant compounds are useful in a combination therapy with current standard of agents, having additive or synergistic activity with one or more known agents.

A combination therapy comprising compounds described herein in combination with one or more known drugs may be used to treat HD regardless of whether HD is responsive to the known drug.

Aspects of the present description include the use of a compound of Formula (I) or a form thereof in a combination therapy for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof and an effective amount of one or more agent(s).

Aspects of the present description include the use of a compound of Formula (I) or a form thereof in a combination therapy for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof and an effective amount of one or more agent(s).

In an aspect of a use or method provided herein, compounds of Formula (I) or a form thereof used in combination with one or more additional agents can be administered to a subject or contacted with a subject or patient cell(s) prior to, concurrently with, or subsequent to administering to the subject or patient or contacting the cell with an additional agent(s). A compound(s) of Formula (I) or a form thereof and an additional agent(s) can be administered to a subject or contacted with a cell in single composition or different compositions. In a specific aspect, a compound(s) of Formula (I) or a form thereof is used in combination with gene therapy to inhibit HTT expression (using, e.g., viral delivery vectors) or the administration of another small molecule HTT inhibitor. In another specific aspect, a compound(s) of Formula (I) or a form thereof are used in combination with cell replacement using differentiated non-mutant HTT stem cells. In another specific aspect, a compound(s) of Formula (I) or a form thereof are used in combination with cell replacement using differentiated HTT stem cells.

In one aspect, provided herein is the use of compounds of Formula (I) or a form thereof in combination with supportive standard of care therapies, including palliative care.

An aspect of the present description includes the use of a compound of Formula (I) or a form thereof in the preparation of a kit comprising the compound of Formula (I) or a form thereof and instructions for administering an effective amount of the compound of Formula (I) or a form thereof and an effective amount of one or more agent(s) in a combination therapy for treating or ameliorating HD in a subject in need thereof.

Accordingly, the present description relates to use of a compound of Formula (I) or a form thereof for treating or ameliorating HD. In accordance with the use of the present description, compounds that are useful in selectively treating or ameliorating HD, have been identified and use of these compounds for treating or ameliorating HD has been provided.

One aspect of the use of the present description relates to use of a compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof to the subject.

One aspect of the use of the present description relates to a method of use of a compound of Formula (I) or a form thereof for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound to the subject.

An aspect of the use of the present description relates to use of a compound of Formula (I) or a form thereof in the manufacture of a medicament for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the medicament to the subject.

An aspect of the use of the present description relates to use of a compound of Formula (I) or a form thereof in the preparation of a kit comprising the compound of Formula (I) or a form thereof and instructions for administering the compound for treating or ameliorating HD in a subject in need thereof.

In one respect, for each of such aspects, the subject is treatment naive. In another respect, for each of such aspects, the subject is not treatment naive.

As used herein, the phrases “a method or use for a compound for treating or ameliorating HD (Huntington's Disease),” “a method of use for a compound for treating or ameliorating HD” or “a use for a compound for treating or ameliorating HD” coextensively refer to a plurality of potential uses of a compound which would be known to those of skill in the art including, without limitation: (i) a method of use of a compound for treating or ameliorating HD; (ii) a use of a compound for treating or ameliorating HD; (iii) a use of a compound in the preparation of a medicament for treating or ameliorating HD; (iv) a use of a compound in the preparation of a pharmaceutical composition for treating or ameliorating HD; (iv) a use of a compound in the preparation of a kit for treating or ameliorating HD; and, the like.

As used herein, the term “treating” refers to: (i) preventing a disease, disorder or condition from occurring in a subject that may be predisposed to the disease, disorder and/or condition but has not yet been diagnosed as having the disease, disorder and/or condition; (ii) inhibiting a disease, disorder or condition, i.e., arresting the development thereof; and/or (iii) relieving a disease, disorder or condition, i.e., causing regression of the disease, disorder and/or condition.

As used herein, the term “subject” refers to an animal or any living organism having sensation and the power of voluntary movement, and which requires oxygen and organic food.

Nonlimiting examples include members of the human, primate, equine, porcine, bovine, murine, rattus, canine and feline specie. In some aspects, the subject is a mammal or a warm-blooded vertebrate animal. In other aspects, the subject is a human. As used herein, the term “patient” may be used interchangeably with “subject” and “human”.

As used herein, the terms “effective amount” or “therapeutically effective amount” mean an amount of compound of Formula (I) or a form, composition or medicament thereof effective in inhibiting the above-noted diseases and thus producing the desired therapeutic, ameliorative, inhibitory or preventative effect in a subject in need thereof.

The dose administered to achieve an effective target plasma concentration may also be administered based upon the weight of the subject or patient. Doses administered on a weight basis may be in the range of about 0.001 mg/kg/day to about 3500 mg/kg/day, or about 0.001 mg/kg/day to about 3000 mg/kg/day, or about 0.001 mg/kg/day to about 2500 mg/kg/day, or about 0.001 mg/kg/day to about 2000 mg/kg/day, or about 0.001 mg/kg/day to about 1500 mg/kg/day, or about 0.001 mg/kg/day to about 1000 mg/kg/day, or about 0.001 mg/kg/day to about 500 mg/kg/day, or about 0.001 mg/kg/day to about 250 mg/kg/day, or about 0.001 mg/kg/day to about 100 mg/kg/day, or about 0.001 mg/kg/day to about 75 mg/kg/day, or about 0.001 mg/kg/day to about 50 mg/kg/day, or about 0.001 mg/kg/day to about 40 mg/kg/day, or about 0.001 mg/kg/day to about 30 mg/kg/day, or about 0.001 mg/kg/day to about 20 mg/kg/day, or about 0.001 mg/kg/day to about 10 mg/kg/day, or about 0.01 mg/kg/day to about 2000 mg/kg/day, or about 0.01 mg/kg/day to about 1500 mg/kg/day, or about 0.01 mg/kg/day to about 1000 mg/kg/day, or about 0.01 mg/kg/day to about 600 mg/kg/day, or about 0.01 mg/kg/day to about 500 mg/kg/day, or about 0.01 mg/kg/day to about 300 mg/kg/day, or about 0.015 mg/kg/day to about 200 mg/kg/day, or about 0.02 mg/kg/day to about 100 mg/kg/day, or about 0.025 mg/kg/day to about 100 mg/kg/day, or about 0.03 mg/kg/day to about 100 mg/kg/day, wherein said amount is orally administered once (once in approximately a 24 hour period), twice (once in approximately a 12 hour period) or thrice (once in approximately an 8 hour period) daily according to subject weight.

In certain aspects, the effective amount will be in a range of from about 0.001 mg/kg/day to about 500 mg/kg/day, or about 0.01 mg/kg/day to about 500 mg/kg/day, or about 0.1 mg to about 500 mg/kg/day, or about 1.0 mg/day to about 500 mg/kg/day, in single, divided, or a continuous dose for a patient or subject having a weight in a range of between about 40 to about 200 kg (which dose may be adjusted for patients or subjects above or below this range, particularly children under 40 kg). The typical adult subject is expected to have a median weight in a range of about 70 kg.

In another aspect, where daily doses are adjusted based upon the weight of the subject or patient, compounds described herein may be formulated for delivery at about 0.02, 0.025, 0.03, 0.05, 0.06, 0.075, 0.08, 0.09, 0.10, 0.20, 0.25, 0.30, 0.50, 0.60, 0.75, 0.80, 0.90, 1.0, 1.10, 1.20, 1.25, 1.50, 1.75, 2.0, 3.0, 5.0, 10, 20, 30, 40, 50, 100, 150, 200, 250, 300, 400 or 500 mg/kg/day.

Daily doses adjusted based upon the weight of the subject or patient may be administered as a single, divided, or continuous dose. In aspects where a dose of compound is given more than once per day, the dose may be administered twice, thrice, or more times per day.

Within the scope of the present description, the “effective amount” of a compound of Formula (I) or a form thereof for use in the manufacture of a medicament, for use in the preparation of a pharmaceutical kit or in a method of use for treating or ameliorating HD in a subject in need thereof is intended to include an amount in a range of from about 0.001 mg/kg/day to about 3500 mg/kg/day, or about 0.001 mg/kg/day to about 3000 mg/kg/day, or about 0.001 mg/kg/day to about 2500 mg/kg/day, or about 0.001 mg/kg/day to about 2000 mg/kg/day, or about 0.001 mg/kg/day to about 1500 mg/kg/day, or about 0.001 mg/kg/day to about 1000 mg/kg/day, or about 0.001 mg/kg/day to about 500 mg/kg/day, or about 0.001 mg/kg/day to about 250 mg/kg/day, or about 0.001 mg/kg/day to about 100 mg/kg/day, or about 0.001 mg/kg/day to about 75 mg/kg/day, or about 0.001 mg/kg/day to about 50 mg/kg/day, or about 0.001 mg/kg/day to about 40 mg/kg/day, or about 0.001 mg/kg/day to about 30 mg/kg/day, or about 0.001 mg/kg/day to about 20 mg/kg/day, or about 0.001 mg/kg/day to about 10 mg/kg/day, or about 0.01 mg/kg/day to about 2000 mg/kg/day, or about 0.01 mg/kg/day to about 1500 mg/kg/day, or about 0.01 mg/kg/day to about 1000 mg/kg/day, or about 0.01 mg/kg/day to about 600 mg/kg/day, or about 0.01 mg/kg/day to about 500 mg/kg/day, or about 0.01 mg/kg/day to about 300 mg/kg/day, or about 0.015 mg/kg/day to about 200 mg/kg/day, or about 0.02 mg/kg/day to about 100 mg/kg/day, or about 0.025 mg/kg/day to about 100 mg/kg/day, or about 0.03 mg/kg/day to about 100 mg/kg/day, wherein said amount is administered once (once in approximately a 24 hour period; i.e., “q.d.”), twice (once in approximately a 12 hour period; i.e., “b.i.d.” or “q.12 h”), thrice (once in approximately an 8 hour period; i.e., “t.i.d.” or “q.8 h”), or four times (once in approximately a 6 hour period; i.e., “q.d.s.”, “q.i.d.” or “q.6 h”) daily according to subject weight.

Such amounts may further include an amount in a range of from about 0.001 mg to about 3500 mg administered daily; 0.001 mg to about 3000 mg administered daily; 0.001 mg to about 2500 mg administered daily; 0.001 mg to about 2000 mg administered daily; 0.001 mg to about 1500 mg administered daily; 0.001 mg to about 1000 mg administered daily; 0.001 mg to about 500 mg administered daily; 0.001 mg to about 250 mg administered daily; 1.0 mg to about 3500 mg administered daily; 1.0 mg to about 1500 mg administered daily; 1.0 mg to about 1000 mg administered daily; 10.0 mg to about 600 mg administered daily; 0.5 mg to about 2000 mg administered daily; or, an amount in a range of from about 5.0 mg to about 300 mg administered daily.

For example, the effective amount may be the amount required to treat HD in a subject or, more specifically, in a human. The effective amount for a subject will depend upon various factors, including the subject's body weight, size and health. Effective amounts for a given patient can be determined by routine experimentation that is within the skill and judgment of the clinician.

For any compound, the effective amount can be estimated initially either in cell culture assays or in relevant animal models, such as a mouse, chimpanzee, marmoset or tamarin animal model. Relevant animal models may also be used to determine the appropriate concentration range and route of administration. Such information can then be used to determine useful doses and routes for administration in humans. Therapeutic efficacy and toxicity may be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., ED₅₀ (the dose therapeutically effective in 50% of the population) and LD₅₀ (the dose lethal to 50% of the population). The dose ratio between therapeutic and toxic effects is therapeutic index, and can be expressed as the ratio, LD₅₀/ED₅₀. In some aspects, the effective amount is such that a large therapeutic index is achieved. In further aspects, the dosage is within a range of circulating concentrations that include an ED₅₀ with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed, sensitivity of the patient, and the route of administration.

More specifically, the concentration-biological effect relationships observed with regard to a compound of Formula (I) or a form thereof indicate a target plasma concentration ranging from approximately 0.001 μg/mL to approximately 50 μg/mL, from approximately 0.01 μg/mL to approximately 20 μg/mL, from approximately 0.05 μg/mL to approximately 10 μg/mL, or from approximately 0.1 μg/mL to approximately 5 μg/mL. To achieve such plasma concentrations, the compounds described herein may be administered at doses that vary, such as, for example, without limitation, from 0.1 ng to 10,000 mg, depending upon the route of administration in single, divided, or continuous doses for a patient weighing between about 10 to about 100 kg (which dose may be adjusted for patients within this weight range, particularly for children under 40 kg).

The exact dosage will be determined by the practitioner, in light of factors related to the subject. Dosage and administration may be adjusted to provide sufficient levels of the active agent(s) or to maintain the desired effect. Factors which may be taken into account include the severity of the disease state, general health of the subject, ethnicity, age, weight, gender, diet, time of day and frequency of administration, drug combination(s), reaction sensitivities, experience with other therapies, and tolerance/response to therapy. Long-acting pharmaceutical compositions may be administered every 2, 3 or 4 days, once every week, or once every two weeks depending on half-life and clearance rate of the particular formulation.

The compounds and compositions described herein may be administered to the subject via any drug delivery route known in the art. Nonlimiting examples include oral, ocular, rectal, buccal, topical, nasal, sublingual, transdermal, subcutaneous, intramuscular, intraveneous (bolus and infusion), intracerebral, and pulmonary routes of administration.

In one aspect, provided herein are methods for modulating the amount of HTT (huntingtin protein), comprising contacting a human cell with a compound of Formula (I) or a form thereof. In a specific aspect, provided herein are methods for modulating the amount of HTT, comprising contacting a human cell with a compound of Formula (I) or a form thereof that modulates the expression of HTT. The human cell can be contacted with a compound of Formula (I) or a form thereof in vitro, or in vivo, e.g., in a non-human animal or in a human. In a specific aspect, the human cell is from or in a human. In another specific aspect, the human cell is from or in a human with HD. In another specific aspect, the human cell is from or in a human with HD, caused by a CAG repeat in the Htt gene, resulting in a loss of HTT expression and/or function. In another aspect, the human cell is from a human with HD. In another aspect, the human cell is in a human with HD. In one aspect, the compound is a form of the compound of Formula (I).

In a specific aspect, provided herein is a method for enhancing the inhibition of mutant HTT transcribed from the Htt gene, comprising contacting a human cell with a compound of Formula (I) or a form thereof. The human cell can be contacted with a compound of Formula (I) or a form thereof in vitro, or in vivo, e.g., in a non-human animal or in a human. In a specific aspect, the human cell is from or in a human. In another specific aspect, the human cell is from or in a human with HD. In another specific aspect, the human cell is from or in a human with HD, caused by a CAG repeat in the Htt gene, resulting in a loss of wild-type “normal” HTT expression and/or function. In another aspect, the human cell is from a human with HD. In another aspect, the human cell is in a human with HD. In one aspect, the compound is a form of the compound of Formula (I).

In another aspect, provided herein is a method for modulating the inhibition of mutant HTT transcribed from the Htt gene, comprising administering to a non-human animal model for HD a compound of Formula (I) or a form thereof. In a specific aspect, provided herein is a method for modulating the inhibition of mutant HTT transcribed from the Htt gene, comprising administering to a non-human animal model for HD a compound of Formula (I) or a form thereof. In a specific aspect, the compound is a form of the compound of Formula (I).

In another aspect, provided herein is a method for decreasing the amount of mutant HTT, comprising contacting a human cell with a compound of Formula (I) or a form thereof. In a specific aspect, provided herein is a method for decreasing the amount of mutant HTT, comprising contacting a human cell with a compound of Formula (I) that inhibits the transcription of mutant HTT (huntingtin mRNA) from the Htt gene. In another specific aspect, provided herein is a method for decreasing the amount of HTT, comprising contacting a human cell with a compound of Formula (I) that inhibits the expression of mutant HTT transcribed from the Htt gene. The human cell can be contacted with a compound of Formula (I) or a form thereof in vitro, or in vivo, e.g., in a non-human animal or in a human. In a specific aspect, the human cell is from or in a human. In another specific aspect, the human cell is from or in a human with HD. In another specific aspect, the human cell is from or in a human with HD, caused by a CAG repeat in the Htt gene, resulting in a loss of HTT expression and/or function. In another aspect, the human cell is from a human with HD. In another aspect, the human cell is in a human with HD. In one aspect, the compound is a form of the compound of Formula (I).

In certain aspects, treating or ameliorating HD with a compound of Formula (I) or a form thereof (alone or in combination with an additional agent) has a therapeutic effect and/or beneficial effect. In a specific aspect, treating HD with a compound of Formula (I) or a form thereof (alone or in combination with an additional agent) results in one, two or more of the following effects: (i) reduces or ameliorates the severity of HD; (ii) delays onset of HD; (iii) inhibits the progression of HD; (iv) reduces hospitalization of a subject; (v) reduces hospitalization length for a subject; (vi) increases the survival of a subject; (vii) improves the quality of life for a subject; (viii) reduces the number of symptoms associated with HD; (ix) reduces or ameliorates the severity of a symptom(s) associated with HD; (x) reduces the duration of a symptom associated with HD; (xi) prevents the recurrence of a symptom associated with HD; (xii) inhibits the development or onset of a symptom of HD; and/or (xiii) inhibits of the progression of a symptom associated with HD.

Metabolites

Also included within the scope of the present description are the use of in vivo metabolic products of the compounds described herein. Such products may result, for example, from the oxidation, reduction, hydrolysis, amidation, esterification and the like of the administered compound, primarily due to enzymatic processes. Accordingly, the description includes the use of compounds produced by a process comprising contacting a compound described herein with a mammalian tissue or a mammal for a period of time sufficient to yield a metabolic product thereof.

Such products typically are identified by preparing a radio-labeled isotopologue (e.g., ¹⁴C or ³H) of a compound described herein, administering the radio-labeled compound in a detectable dose (e.g., greater than about 0.5 mg/kg) to a mammal such as a rat, mouse, guinea pig, dog, monkey or human, allowing sufficient time for metabolism to occur (typically about 30 seconds to about 30 hours), and identifying the metabolic conversion products from urine, bile, blood or other biological samples. The conversion products are easily isolated since they are “radiolabeled” by virtue of being isotopically-enriched (others are isolated by the use of antibodies capable of binding epitopes surviving in the metabolite). The metabolite structures are determined in conventional fashion, e.g., by MS or NMR analysis. In general, analysis of metabolites may be done in the same way as conventional drug metabolism studies well-known to those skilled in the art. The conversion products, so long as they are not otherwise found in vivo, are useful in diagnostic assays for therapeutic dosing of the compounds described herein even if they possess no biological activity of their own.

Pharmaceutical Compositions

Aspects of the present description include the use of a compound of Formula (I) or a form thereof in a pharmaceutical composition for treating or ameliorating HD in a subject in need thereof, comprising administering an effective amount of the compound of Formula (I) or a form thereof in admixture with one or more pharmaceutically acceptable excipient(s).

An aspect of the present description includes the use of a pharmaceutical composition of the compound of Formula (I) or a form thereof in the preparation of a kit comprising the pharmaceutical composition of the compound of Formula (I) or a form thereof and instructions for administering the compound for treating or ameliorating HD in a subject in need thereof.

As used herein, the term “composition” means a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from combination of the specified ingredients in the specified amounts.

The pharmaceutical composition may be formulated to achieve a physiologically compatible pH, ranging from about pH 3 to about pH 11. In some aspects, the pharmaceutical composition is formulated to achieve a pH of from about pH 3 to about pH 7. In other aspects, the pharmaceutical composition is formulated to achieve a pH of from about pH 5 to about pH 8.

The term “pharmaceutically acceptable excipient” refers to an excipient for administration of a pharmaceutical agent, such as the compounds described herein. The term refers to any pharmaceutical excipient that may be administered without undue toxicity. Pharmaceutically acceptable excipients may be determined in part by the particular composition being administered, as well as by the particular mode of administration and/or dosage form. Nonlimiting examples of pharmaceutically acceptable excipients include carriers, solvents, stabilizers, adjuvants, diluents, etc. Accordingly, there exists a wide variety of suitable formulations of pharmaceutical compositions for the instant compounds described herein (see, e.g., Remington's Pharmaceutical Sciences).

Suitable excipients may be carrier molecules that include large, slowly metabolized macromolecules such as proteins, polysaccharides, polylactic acids, polyglycolic acids, polymeric amino acids, amino acid copolymers, and inactive antibodies. Other exemplary excipients include antioxidants such as ascorbic acid; chelating agents such as EDTA; carbohydrates such as dextrin, hydroxyalkylcellulose, hydroxyalkylmethylcellulose (e.g., hydroxypropylmethylcellulose, also known as HPMC), stearic acid; liquids such as oils, water, saline, glycerol and ethanol; wetting or emulsifying agents; pH buffering substances; and the like. Liposomes are also included within the definition of pharmaceutically acceptable excipients.

The pharmaceutical compositions described herein may be formulated in any form suitable for the intended use described herein. Suitable formulations for oral administration include solids, liquid solutions, emulsions and suspensions, while suitable inhalable formulations for pulmonary administration include liquids and powders. Alternative formulations include syrups, creams, ointments, tablets, and lyophilized solids which can be reconstituted with a physiologically compatible solvent prior to administration.

When intended for oral use for example, tablets, troches, lozenges, aqueous or oil suspensions, non-aqueous solutions, dispersible powders or granules (including micronized particles or nanoparticles), emulsions, hard or soft capsules, syrups or elixirs may be prepared. Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions, and such compositions may contain one or more agents including sweetening agents, flavoring agents, coloring agents, and preserving agents, in order to provide a palatable preparation.

Pharmaceutically acceptable excipients suitable for use in conjunction with tablets include, for example, inert diluents, such as celluloses, calcium or sodium carbonate, lactose, calcium or sodium phosphate; disintegrating agents, such as croscarmellose sodium, cross-linked povidone, maize starch, or alginic acid; binding agents, such as povidone, starch, gelatin or acacia; and lubricating agents, such as magnesium stearate, stearic acid, or talc. Tablets may be uncoated or may be coated by known techniques including microencapsulation to delay disintegration and adsorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate alone or with a wax may be employed.

Formulations for oral use may be also presented as hard gelatin capsules where the active ingredient is mixed with an inert solid diluent, for example celluloses, lactose, calcium phosphate, or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with non-aqueous or oil medium, such as glycerin, propylene glycol, polyethylene glycol, peanut oil, liquid paraffin, or olive oil.

In other aspects, pharmaceutical compositions described herein may be formulated as suspensions comprising a compound of Formula (I) or a form thereof in admixture with one or more pharmaceutically acceptable excipient(s) suitable for the manufacture of a suspension. In yet other aspects, pharmaceutical compositions described herein may be formulated as dispersible powders and granules suitable for preparation of a suspension by the addition of one or more excipient(s).

Excipients suitable for use in connection with suspensions include suspending agents, such as sodium carboxymethylcellulose, methylcellulose, hydroxypropyl methylcelluose, sodium alginate, polyvinylpyrrolidone, gum tragacanth, gum acacia, dispersing or wetting agents such as a naturally occurring phosphatide (e.g., lecithin), a condensation product of an alkylene oxide with a fatty acid (e.g., polyoxyethylene stearate), a condensation product of ethylene oxide with a long chain aliphatic alcohol (e.g., heptadecaethyleneoxycethanol), a condensation product of ethylene oxide with a partial ester derived from a fatty acid and a hexitol anhydride (e.g., polyoxyethylene sorbitan monooleate); and thickening agents, such as carbomer, beeswax, hard paraffin, or cetyl alcohol. The suspensions may also contain one or more preservatives such as acetic acid, methyl and/or n-propyl p-hydroxy-benzoate; one or more coloring agents; one or more flavoring agents; and one or more sweetening agents such as sucrose or saccharin.

The pharmaceutical compositions described herein may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, such as olive oil or arachis oil, a mineral oil, such as liquid paraffin, or a mixture of these. Suitable emulsifying agents include naturally-occurring gums, such as gum acacia and gum tragacanth; naturally occurring phosphatides, such as soybean lecithin, esters or partial esters derived from fatty acids; hexitol anhydrides, such as sorbitan monooleate; and condensation products of these partial esters with ethylene oxide, such as polyoxyethylene sorbitan monooleate. The emulsion may also contain sweetening and flavoring agents. Syrups and elixirs may be formulated with sweetening agents, such as glycerol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative, a flavoring or a coloring agent.

Additionally, the pharmaceutical compositions described herein may be in the form of a sterile injectable preparation, such as a sterile injectable aqueous emulsion or oleaginous suspension. Such emulsion or suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, such as a solution in 1,2-propanediol. The sterile injectable preparation may also be prepared as a lyophilized powder. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile fixed oils may be employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or di-glycerides. In addition, fatty acids such as oleic acid may likewise be used in the preparation of injectables.

The compounds described herein may be substantially insoluble in water and sparingly soluble in most pharmaceutically acceptable protic solvents and vegetable oils, but generally soluble in medium-chain fatty acids (e.g., caprylic and capric acids) or triglycerides and in propylene glycol esters of medium-chain fatty acids. Thus, contemplated in the description are compounds which have been modified by substitutions or additions of chemical or biochemical moieties which make them more suitable for delivery (e.g., increase solubility, bioactivity, palatability, decrease adverse reactions, etc.), for example by esterification, glycosylation, PEGylation, etc.

In some aspects, the compound described herein is formulated for oral administration in a lipid-based composition suitable for low solubility compounds. Lipid-based formulations can generally enhance the oral bioavailability of such compounds. As such, pharmaceutical compositions described herein may comprise a effective amount of a compound of Formula (I) or a form thereof, together with at least one pharmaceutically acceptable excipient selected from medium chain fatty acids or propylene glycol esters thereof (e.g., propylene glycol esters of edible fatty acids such as caprylic and capric fatty acids) and pharmaceutically acceptable surfactants, such as polysorbate 20 or 80 (also referred to as Tween® 20 or Tween® 80, respectively) or polyoxyl 40 hydrogenated castor oil.

In other aspects, the bioavailability of low solubility compounds may be enhanced using particle size optimization techniques including the preparation of nanoparticles or nanosuspensions using techniques known to those skilled in the art. The compound forms present in such preparations include amorphous, partially amorphous, partially crystalline or crystalline forms.

In alternative aspects, the pharmaceutical composition may further comprise one or more aqueous solubility enhancer(s), such as a cyclodextrin. Nonlimiting examples of cyclodextrin include hydroxypropyl, hydroxyethyl, glucosyl, maltosyl and maltotriosyl derivatives of α-, β-, and γ-cyclodextrin, and hydroxypropyl-β-cyclodextrin (HPBC). In some aspects, the pharmaceutical composition further comprises HPBC in a range of from about 0.1% to about 20%, from about 1% to about 15%, or from about 2.5% to about 10%. The amount of solubility enhancer employed may depend on the amount of the compound in the composition.

Preparation of Compounds

Compounds of Formula (I) can be prepared using reagents and methods known in the art, including the methods provided in International Application No. PCT/US2013/025292, filed on Feb. 8, 2013, and published as International Publication No. WO 2013/119916 on Aug. 15, 2013, the entire contents of which are incorporated herein by reference (see in particular, General Synthetic Methods, Schemes A-J, at paragraphs [001126] to [001159]; and Specific Synthetic Examples, at paragraphs [001160] to [001573] and Table 1).

Biological Examples

The following in vitro biological examples demonstrate the usefulness of the compounds of the present description for treating Huntington's disease.

To describe in more detail and assist in understanding the present description, the following non-limiting biological examples are offered to more fully illustrate the scope of the description and are not to be construed as specifically limiting the scope thereof. Such variations of the present description that may be now known or later developed, which would be within the purview of one skilled in the art to ascertain, are considered to fall within the scope of the present description and as hereinafter claimed.

Compounds of Formula (I) were tested using the Meso Scale Discovery (MSD) Assay provided in International Application No. PCT/US2016/066042, filed on Dec. 11, 2016 and claiming priority to U.S. Provisional Application 62/265,652 filed on Dec. 10, 2015, published as International Publication No. WO 2017/100726 on Jun. 15, 2017, the entire contents of which are incorporated herein by reference.

The Endogenous Huntingtin Protein assay used in Example 1 was developed using the ELISA-based MSD electrochemiluminescence assay platform.

Example 1

Endogenous Huntingtin Protein Assay

Meso Scale Discovery (MSD) 96-well or 384-well plates were coated overnight at 4° C. with MW1 (expanded polyglutamine) or MAB2166 monoclonal antibody (for capture) at a concentration of 1 μg/mL in PBS (30 μL per well). Plates were then washed three times with 300 L wash buffer (0.05% Tween-20 in PBS) and blocked (100 μL blocking buffer; 5% BSA in PBS) for 4-5 hours at room temperature with rotational shaking and then washed three times with wash buffer.

Samples (25 μL) were transferred to the antibody-coated MSD plate and incubated overnight at 4° C. After removal of the lysates, the plate was washed three times with wash buffer, and 25 μL of #5656S (Cell signaling; rabbit monoclonal) secondary antibody (diluted to 0.25 μg/mL in 0.05% Tween-20 in blocking buffer) was added to each well and incubated with shaking for 1 Hour at room temperature. Following incubation with the secondary antibody, the wells were rinsed with wash buffer after which 25 μL of goat anti-rabbit SULFO TAG secondary detection antibody (required aspect of the MSD system) (diluted to 0.25 μg/mL in 0.05% Tween-20 in blocking buffer) was added to each well and incubated with shaking for 1 hour at room temperature. After rinsing three times with wash buffer, 150 μL of read buffer T with surfactant (MSD) were added to each empty well, and the plate was imaged on a SI 6000 imager (MSD) according to manufacturers' instructions provided for 96- or 384-well plates. The resulting IC₅₀ values (μM) for compounds tested are shown in Table 1.

As shown in Table 1, test compounds described herein had the following IC₅₀ values, an IC₅₀ value between >3 μM and <33 μM is indicated by a single star (*), an IC₅₀ value between >1 μM and <3 μM is indicated by two stars (**), an IC₅₀ value between >0.5 μM and <1 μM is indicated by three stars (***), an IC₅₀ value between >0.1 μM and <0.5 μM is indicated by four stars (****) and an IC₅₀ value of <0.1 μM is indicated by five stars (*****).

TABLE 1 Cpd IC₅₀ 29 * 72 * 74 ** 75 ** 88 * 94 * 96 * 107 * 108 * 109 ** 114 * 118 * 120 ** 121 * 123 * 124 * 125 * 128 * 129 * 131 * 133 *** 135 ** 136 * 137 ** 138 ** 141 ** 162 * 163 * 170 * 179 * 191 * 192 * 194 * 199 * 209 **** 219 * 228 * 229 * 258 * 259 * 261 * 268 * 269 *** 271 ** 272 *** 287 **** 302 **** 305 **** 306 **** 308 *** 309 ** 318 ** 336 * 337 * 350 * 351 * 356 * 400 * 401 * 409 ** 410 *** 412 * 413 ***** 420 ** 421 * 422 **** 423 * 428 * 438 *** 441 ** 442 * 444 * 450 * 451 * 452 **** 460 * 461 * 462 ** 463 * 465 * 474 *** 476 * 477 ** 479 * 480 **** 481 * 482 * 486 *** 487 *** 489 * 490 * 502 ***** 503 ** 504 **** 505 * 506 * 507 * 516 ***** 530 * 531 * 532 ** 540 ** 545 * 546 ** 549 * 550 * 552 * 553 * 555 * 556 * 557 * 566 **** 567 * 568 ** 569 ** 578 * 579 * 580 * 581 ** 582 * 584 * 585 *** 586 * 587 **** 588 *** 589 * 590 * 591 * 592 * 593 ** 594 ** 595 ** 599 ** 606 * 608 *** 609 * 612 ** 613 ** 624 *** 627 ** 628 * 632 ** 633 * 635 ** 636 * 637 *** 639 * 641 * 649 *** 653 ***** 654 ***** 655 **** 656 **** 662 *** 665 * 667 ** 668 *** 671 ** 673 * 674 * 677 * 679 * 683 * 684 * 685 * 688 * 696 ***** 702 ** 705 *** 706 * 709 * 710 **** 711 **** 713 **** 714 * 718 **** 719 ***** 720 * 721 *** 723 * 727 * 733 ** 734 * 735 * 736 * 738 **** 739 *** 741 *** 748 *** 749 * 750 * 751 * 752 **** 753 **** 754 *** 755 ** 756 **** 763 **** 766 *** 768 ** 770 * 771 *** 773 * 774 * 776 * 777 * 780 ** 787 * 791 ***** 793 ** 796 ***** 836 * 837 * 838 * 839 * 840 * 841 * 842 * 843 * 844 * 845 * 846 * 847 * 848 * 849 * 850 * 851 * 852 * 853 * 854 * 855 * 856 ** 857 *** 858 ** 859 ** 860 * 861 * 862 ** 863 ** 864 ***** 865 * 866 * 867 * 868 ** 869 ***** 870 ***** 871 ***** 872 ***** 873 **** 874 **** 875 ***** 876 ** 877 *****

Without regard to whether a document cited herein was specifically and individually indicated as being incorporated by reference, all documents referred to herein are incorporated by reference into the present application for any and all purposes to the same extent as if each individual reference was fully set forth herein.

Having now fully described the subject matter of the claims, it will be understood by those having ordinary skill in the art that the same can be performed within a wide range of equivalents without affecting the scope of the subject matter or aspects described herein. It is intended that the appended claims be interpreted to include all such equivalents. 

What is claimed is:
 1. A method of inhibiting, relieving, or ameliorating HD (Huntington's Disease) in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I):

or a form thereof, wherein: w₁ and w₅ are independently C—R_(a) or N; w₂ is C—R_(b) or N; w₃, w₄ and w₇ are independently C—R₁, C—R₂, C—R_(a) or N; w₆ is C—R₁, C—R₂, C—R_(c) or N; wherein one of w₃, w₄, w₆ and w₇ is C—R₁ and one other of w₃, w₄, w₆ and w₇ is C—R₂, provided that, when w₃ is C—R₁, then w₆ is C—R₂ and w₄ and w₇ are independently C—R_(a) or N; or, when w₃ is C—R₂, then w₆ is C—R₁ and w₄ and w₇ are independently C—R_(a) or N; or, when w₄ is C—R₁, then w₇ is C—R₂ and w₃ is C—R_(a) or N and w₆ is C—R_(c) or N; or, when w₄ is C—R₂, then w₇ is C—R₁ and w₃ is C—R_(a) or N and w₆ is C—R_(c) or N; and, wherein any one, two or three of w₁, w₂, w₃, w₄, w₅, w₆ and w₇ may optionally be N; R₁ is C₁₋₈alkyl, amino, C₁₋₈alkyl-amino, (C₁₋₈ alkyl)₂-amino, C₁₋₈alkoxy-C₁₋₈ alkyl-amino, (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino, (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino, amino-C₁₋₈alkyl, C₁₋₈alkyl-amino-C₁₋₈alkyl, (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl, C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkyl, (C₁₋₈alkoxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl, (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl, amino-C₁₋₈alkyl-amino, (amino-C₁₋₈ alkyl)₂-amino, (amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino, C₁₋₈alkyl-amino-C₁₋₈alkyl-amino, (C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino, (C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino, (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino, [(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino, amino-C₁₋₈alkoxy, C₁₋₈alkyl-amino-C₁₋₈alkoxy, (C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy, C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy, C₁₋₈alkoxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy, (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy, amino-C₂₋₈alkenyl, C₁₋₈ alkyl-amino-C₂₋₈ alkenyl, (C₁₋₈ alkyl)₂-amino-C₂₋₈ alkenyl, amino-C₂₋₈ alkynyl, C₁₋₈alkyl-amino-C₂₋₈alkynyl, (C₁₋₈alkyl)₂-amino-C₂₋₈alkynyl, halo-C₁₋₈alkyl-amino, (halo-C₁₋₈alkyl)₂-amino, (halo-C₁₋₈alkyl)(C₁₋₈alkyl)amino, hydroxy-C₁₋₈alkyl, hydroxy-C₁₋₈alkoxy-C₁₋₈alkyl, hydroxy-C₁₋₈alkyl-amino, (hydroxy-C₁₋₈alkyl)₂-amino, (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino, hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl, (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl, (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl, hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkoxy, (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkoxy, (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkoxy, hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl-amino, (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino, (hydroxy-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino, (hydroxy-C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino, (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl-amino, [(hydroxy-C₁₋₈ alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈alkyl)amino, [(hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl](C₁₋₈alkyl)amino, heterocyclyl, heterocyclyl-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkoxy, heterocyclyl-amino, (heterocyclyl)(C₁₋₈alkyl)amino, heterocyclyl-amino-C₁₋₈alkyl, heterocyclyl-C₁₋₈alkyl-amino, (heterocyclyl-C₁₋₈alkyl)₂-amino, (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, heterocyclyl-C₁₋₈alkyl-amino-C₁₋₈alkyl, (heterocyclyl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl, (heterocyclyl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl, heterocyclyl-oxy, heterocyclyl-carbonyl, heterocyclyl-carbonyl-oxy, C₃₋₁₄cycloalkyl, aryl-C₁₋₈alkyl-amino, (aryl-C₁₋₈alkyl)₂-amino, (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, aryl-C₁₋₈alkyl-amino-C₁₋₈alkyl, (aryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl, (aryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl, heteroaryl, heteroaryl-C₁₋₈alkyl, heteroaryl-C₁₋₈ alkoxy, heteroaryl-amino, heteroaryl-C₁₋₈alkyl-amino, (heteroaryl-C₁₋₈alkyl)₂-amino, (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino, heteroaryl-C₁₋₈alkyl-amino-C₁₋₈alkyl, (heteroaryl-C₁₋₈alkyl)₂-amino-C₁₋₈alkyl or (heteroaryl-C₁₋₈alkyl)(C₁₋₈alkyl)amino-C₁₋₈alkyl; wherein, each instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and heteroaryl is optionally substituted with one, two or three R₃ substituents and optionally, with one additional R₄ substituent; or, wherein, each instance of heterocyclyl, C₃₋₁₄cycloalkyl, aryl and heteroaryl is optionally substituted with one, two, three or four R₃ substituents; R₂ is aryl, aryl-amino, aryl-amino-carbonyl, heterocyclyl, heteroaryl or heteroaryl-amino; wherein, each instance of aryl, heterocyclyl and heteroaryl is optionally substituted with one, two or three R₆ substituents and optionally, with one additional R₇ substituent; R_(a) is, in each instance, independently selected from hydrogen, halogen or C₁₋₈ alkyl; R_(b) is hydrogen, halogen, C₁₋₈ alkyl or C₁₋₈ alkoxy; R_(c) is hydrogen, halogen or C₁₋₈ alkyl; R₃ is, in each instance, independently selected from cyano, halogen, hydroxy, oxo, C₁₋₈ alkyl, halo-C₁₋₈ alkyl, C₁₋₈ alkyl-carbonyl, C₁₋₈ alkoxy, halo-C₁₋₈ alkoxy, C₁₋₈ alkoxy-C₁₋₈ alkyl, C₁₋₈alkoxy-carbonyl, amino, C₁₋₈alkyl-amino, (C₁₋₈alkyl)₂-amino, amino-C₁₋₈alkyl, C₁₋₈alkyl-amino-C₁₋₈alkyl, (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl, amino-C₁₋₈alkyl-amino, C₁₋₈alkyl-amino-C₁₋₈alkyl-amino, (C₁₋₈alkyl-amino-C₁₋₈alkyl)₂-amino, (C₁₋₈alkyl)₂-amino-C₁₋₈alkyl-amino, [(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl]₂-amino, (C₁₋₈alkyl-amino-C₁₋₈alkyl)(C₁₋₈alkyl)amino, [(C₁₋₈alkyl)₂-amino-C₁₋₈alkyl](C₁₋₈ alkyl)amino, C₁₋₈ alkoxy-C₁₋₈alkyl-amino, (C₁₋₈ alkoxy-C₁₋₈alkyl)₂-amino, (C₁₋₈alkoxy-C₁₋₈alkyl)(C₁₋₈ alkyl)amino, C₁₋₈alkyl-carbonyl-amino, C₁₋₈alkoxy-carbonyl-amino, hydroxy-C₁₋₈alkyl, hydroxy-C₁₋₈alkoxy-C₁₋₈ alkyl, hydroxy-C₁₋₈alkyl-amino, (hydroxy-C₁₋₈alkyl)₂-amino or (hydroxy-C₁₋₈alkyl)(C₁₋₈alkyl)amino; R₄ is C₃₋₁₄cycloalkyl, C₃₋₁₄cycloalkyl-C₁₋₈alkyl, C₃₋₁₄cycloalkyl-amino, aryl-C₁₋₈ alkyl, aryl-C₁₋₈alkoxy-carbonyl, aryl-sulfonyloxy-C₁₋₈alkyl, heterocyclyl or heterocyclyl-C₁₋₈alkyl; wherein, each instance of C₃₋₁₄ cycloalkyl, aryl and heterocyclyl is optionally substituted with one, two or three R₅ substituents; R₅ is, in each instance, independently selected from halogen, hydroxy, cyano, nitro, C₁₋₈ alkyl, halo-C₁₋₈ alkyl, C₁₋₈ alkoxy, halo-C₁₋₈ alkoxy, amino, C₁₋₈ alkyl-amino, (C₁₋₈ alkyl)₂-amino or C₁₋₈alkyl-thio; R₆ is, in each instance, independently selected from halogen, hydroxy, cyano, nitro, C₁₋₈ alkyl, C₂₋₈ alkenyl, halo-C₁₋₈ alkyl, hydroxy-C₁₋₈ alkyl, C₁₋₈ alkoxy, halo-C₁₋₈ alkoxy, C₁₋₈alkoxy-C₁₋₈alkyl, amino, C₁₋₈alkyl-amino, (C₁₋₈alkyl)₂-amino or C₁₋₈alkyl-thio; and, R₇ is C₃₋₁₄ cycloalkyl, C₃₋₁₄ cycloalkyl-oxy, aryl, heterocyclyl or heteroaryl; and, wherein the form of the compound is selected from the group consisting of a salt, prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.
 2. The method of claim 1, wherein R₁ is heterocyclyl optionally substituted with one, two or three R₃ substituents and optionally, with one additional R₄ substituent; or, optionally, with one, two, three or four R₃ substituents.
 3. The method of claim 2, wherein R₁ is heterocyclyl selected from azetidinyl, tetrahydrofuranyl, pyrrolidinyl, piperidinyl, piperazinyl, 1,4-diazepanyl, 3,6-dihydropyridinyl, 1,2,5,6-tetrahydropyridinyl, 1,2,3,6-tetrahydropyridinyl, hexahydropyrrolo [3,4-b]pyrrol-(1H)-yl, (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl, (3aR,6aR)-hexahydropyrrolo[3,4-b]pyrrol-(1H)-yl, hexahydropyrrolo[3,4-b]pyrrol-(2H)-yl, (3aS,6aS)-hexahydropyrrolo[3,4-b]pyrrol-(2H)-yl, hexahydropyrrolo[3,4-c]pyrrol-(1H)-yl, (3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-(1H)-yl, 1,3,3a,4,6,6a-hexahydropyrrolo[3,4-c]pyrrolyl, octahydro-5H-pyrrolo[3,2-c]pyridinyl, octahydro-6H-pyrrolo[3,4-b]pyridinyl, (4aR,7aR)-octahydro-6H-pyrrolo[3,4-b]pyridinyl, (4aS,7aS)-octahydro-6H-pyrrolo[3,4-b]pyridinyl, hexahydropyrrolo[1,2-a]pyrazin-(2H)-one, hexahydropyrrolo[1,2-a]pyrazin-(1H)-yl, (7R,8aS)-hexahydropyrrolo[1,2-c]pyrazin-(1H)-yl, (8aS)-hexahydropyrrolo[1,2-c]pyrazin-(1H)-yl, (8aR)-hexahydropyrrolo[1,2-c]pyrazin-(1H)-yl, (8aS)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazinyl, (8aR)-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazinyl, (8aS)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazinyl, (8aR)-1,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrazinyl, (8aS)-octahydropyrrolo[1,2-c]pyrazin-(1H)-yl, (8aR)-octahydropyrrolo[1,2-c]pyrazin-(1H)-yl, octahydro-2H-pyrido[1,2-a]pyrazinyl, (3aR,4aR,7aS)-hexahydro-1H-cyclobuta[1,2-c:1,4-c′]dipyrrol-(3H)-yl, 3-azabicyclo[3.1.0]hexyl, (1R,5S)-3-azabicyclo[3.1.0]hexyl, 8-azabicyclo[3.2.1]octyl, (1R,5S)-8-azabicyclo[3.2.1]octyl, 8-azabicyclo[3.2.1]oct-2-enyl, (1R,5S)-8-azabicyclo[3.2.1]oct-2-enyl, 9-azabicyclo[3.3.1]nonyl, (1R,5S)-9-azabicyclo[3.3.1]nonyl, 2,5-diazabicyclo[2.2.1]heptyl, (1S,4S)-2,5-diazabicyclo[2.2.1]heptyl, 2,5-diazabicyclo[2.2.2]octyl, 3,6-diazabicyclo[3.2.0]heptyl, 3,8-diazabicyclo[3.2.1]octyl, (1R,5S)-3,8-diazabicyclo[3.2.1]octyl, 1,4-diazabicyclo[3.2.2]nonyl, azaspiro[3.3]heptyl, 2,6-diazaspiro[3.3]heptyl, 4,7-diazaspiro[2.5]octyl, 2,6-diazaspiro[3.4]octyl, 2,7-diazaspiro[3.5]nonyl, 5,8-diazaspiro[3.5]nonyl, 2,7-diazaspiro[4.4]nonyl or 6,9-diazaspiro[4.5]decyl; wherein, each instance of heterocyclyl is optionally substituted with one, two or three R₃ substituents and optionally, with one additional R₄ substituents; or, optionally, with one, two, three or four R₃ substituents.
 4. The method of claim 1, wherein R₂ is heteroaryl optionally substituted with one, two or three R₆ substituents and optionally, with one additional R₇ substituent.
 5. The method of claim 4, wherein R₂ is heteroaryl selected from thienyl, 1H-pyrazolyl, 1H-imidazolyl, 1,3-thiazolyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, pyridinyl, pyrimidinyl, 1H-indolyl, 2H-indolyl, 1H-indazolyl, 2H-indazolyl, indolizinyl, benzofuranyl, benzothienyl, 1H-benzimidazolyl, 1,3-benzothiazolyl, 1,3-benzoxazolyl, 9H-purinyl, quinazolinyl, quinoxalinyl, furo[3,2-b]pyridinyl, furo[3,2-c]pyridinyl, furo[2,3-c]pyridinyl, thieno[3,2-c]pyridinyl, thieno[2,3-d]pyrimidinyl, 1H-pyrrolo[2,3-b]pyridinyl, 1H-pyrrolo[2,3-c]pyridinyl, pyrrolo[1,2-a]pyrimidinyl, pyrrolo[1,2-a]pyrazinyl, pyrrolo[1,2-b]pyridazinyl, pyrazolo[1,5-a]pyridinyl, pyrazolo[1,5-a]pyrazinyl, pyrazolo[4,3-b]pyridinyl, pyrazolo[3,4-c]pyridinyl, imidazo[1,2-a]pyridinyl, 3H-imidazo[4,5-b]pyridinyl, imidazo[1,2-a]pyrimidinyl, imidazo[1,2-c]pyrimidinyl, imidazo[1,2-b]pyridazinyl, imidazo[1,2-a]pyrazinyl, imidazo[2,1-b][1,3]thiazolyl, imidazo[2,1-b][1,3,4]thiadiazolyl, [1,3]oxazolo[4,5-b]pyridinyl, [1,2,4]triazolo[1,5-a]pyridinyl, [1,2,4]triazolo[4,3-a]pyridinyl, [1,2,4]triazolo[1,5-a]pyrimidinyl, [1,2,4]triazolo[1,5-b]pyridazinyl, pyrido[1,2-a]pyrimidinyl or pyrido[1,2-a]pyrimidinone; wherein, each instance of heteroaryl is optionally substituted with one, two or three R₆ substituents and optionally, with one additional R₇ substituent.
 6. A method of inhibiting, relieving, or ameliorating HD in a subject in need thereof, comprising administering to the subject an effective amount of a compound or form thereof selected from the group consisting of: 2-(4-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methoxyphenyl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methoxyphenyl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(3,3-dimethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(4-propylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methoxyphenyl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3,3-dimethylpiperazin-1-yl)-2-(4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-benzodioxol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-benzodioxol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-benzodioxol-5-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-benzodioxol-5-yl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-methoxyphenyl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-methoxyphenyl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(3-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-ethylpiperazin-1-yl)-2-(3-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(3-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-methoxyphenyl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methylimidazo[1,2-a]pyridin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-phenyl-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-phenyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-(3,3-dimethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(2,3-dihydro-1,4-benzodioxin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-fluoro-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-chlorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-chlorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-[3-(trifluoromethyl)phenyl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-[4-(trifluoromethyl)phenyl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-methylphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-nitrophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-fluoro-7-(piperidin-4-ylamino)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-(dimethylamino)phenyl]-9-fluoro-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-(dimethylamino)phenyl]-9-fluoro-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-fluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 3-(3,4-dimethoxyphenyl)-8-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-(dimethylamino)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-(dimethylamino)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethylphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethylphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-[3-(dimethylamino)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[3-(dimethylamino)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-(difluoromethoxy)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-(difluoromethoxy)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-nitrophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methylphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-fluoro-4,5-dimethoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-fluoro-4,5-dimethoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3,8-diazabicyclo[3.2.1]oct-3-yl)-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-methoxy-3-(trifluoromethyl)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-methoxy-3-(trifluoromethyl)phenyl]-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-methoxy-3-(trifluoromethyl)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methoxy-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,5-difluoro-4-hydroxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 4-[4-oxo-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-2-yl]benzonitrile 2-(6-methylimidazo[1,2-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methylimidazo[1,2-a]pyrazin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-[3-fluoro-5-(trifluoromethyl)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-fluoro-3-(trifluoromethyl)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[2-methoxy-3-(trifluoromethyl)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,5-difluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-[3-(trifluoromethoxy)phenyl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-methoxy-3-(trifluoromethoxy)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-hydroxy-3-(trifluoromethoxy)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-methoxy-3-(trifluoromethoxy)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-hydroxy-3-(trifluoromethoxy)phenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-4-oxo-7-(piperazin-1-yl)-4H-quinolizine-1-carbonitrile 2-(3-fluoro-4-methoxyphenyl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methoxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,4-dimethoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,4-dimethoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-quinolizin-4-one 2-(5-fluoropyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-fluoropyridin-3-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-chloropyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-chloropyridin-3-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-chloro-6-methoxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1H-indol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1H-indol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[3-(difluoromethoxy)-4-methoxyphenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[3-(difluoromethoxy)-4-hydroxyphenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[3-(difluoromethoxy)-4-methoxyphenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-[3-(difluoromethoxy)-4-hydroxyphenyl]-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-(piperazin-1-yl)-4H-quinolizin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-quinolizin-4-one 2-(3,5-difluorophenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(piperazin-1-yl)-4H-quinolizin-4-one 2-(imidazo[1,2-a]pyridin-7-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(imidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-chloro-4-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-chloro-4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-ethoxy-4-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-ethoxy-4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6,8-dimethylimidazo[1,2-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6,8-dimethylimidazo[1,2-a]pyrazin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(2-methylpyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-[2-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-ethylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,3-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-aminopiperidin-1-yl)-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-(1H-pyrrolo[2,3-b]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-pyrrolo[2,3-b]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(1-methyl-1H-pyrrolo[2,3-b]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-5-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-5-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4,5-dimethoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(4-hydroxypiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(3S)-3-(dimethylamino)pyrrolidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[4-(dimethylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methoxy-3-methylphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 3-[4-oxo-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-2-yl]benzonitrile 2-methoxy-5-[4-oxo-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-2-yl]benzonitrile 2-(3-fluoro-4-hydroxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethoxy-3-fluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[3-fluoro-4-(2,2,2-trifluoroethoxy)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methylphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methylphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-aminopyrrolidin-1-yl]-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(2-methyl-1,3-benzothiazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-(4-methyl-1,3-thiazol-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methyl-1,3-thiazol-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(3S)-3-(propan-2-ylamino)pyrrolidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methoxy-3-nitrophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[3-fluoro-4-(methylsulfanyl)phenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-methyl-1,4-diazepan-1-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-fluoro-6-methoxypyridin-3-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(5-fluoro-6-methoxypyridin-3-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(2-methyl-1,3-benzothiazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-5-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(2-methyl-1,3-benzothiazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methyl-1H-imidazol-1-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methyl-1H-imidazol-1-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-{[2-(methylamino)ethyl]amino}-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-fluoro-6-methoxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,5-difluoro-4-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,5-difluoro-4-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(piperidin-4-ylamino)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-chloro-5-fluorophenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-chloro-5-fluorophenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-(1-methyl-1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-pyrazol-4-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3,3-dimethylpiperazin-1-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,5-dimethoxypyridin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[3-(dimethylamino)pyrrolidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-quinolizin-4-one 7-(4-aminopiperidin-1-yl)-2-(3-fluoro-4-methoxyphenyl)-4H-quinolizin-4-one 7-(4-ethylpiperazin-1-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-quinolizin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-(dimethylamino)pyrrolidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,4R)-3-(dimethylamino)-4-hydroxypyrrolidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-aminopiperidin-1-yl)-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[4-(methylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[(3aR,6aS)-5-methylhexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-3-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-3-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-difluoro-5-methoxyphenyl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-difluoro-5-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3-fluoro-4-methoxyphenyl)-2-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[(3S)-3-(methylamino)pyrrolidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-{4-[(methylamino)methyl]piperidin-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-aminopyrrolidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-{[(3R)-1-methylpyrrolidin-3-yl]amino}-4H-pyrido[1,2-a]pyrimidin-4-one 7-{4-[(dimethylamino)methyl]piperidin-1-yl}-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methoxypyridin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-(pyridin-3-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-methoxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 3-fluoro-5-{7-[(3S)-3-methylpiperazin-1-yl]-4-oxo-4H-pyrido[1,2-a]pyrimidin-2-yl}benzonitrile 3-fluoro-5-[4-oxo-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-2-yl]benzonitrile 2-(3-fluoro-4-methoxyphenyl)-7-[(3′S,4′S)-4′-hydroxy-1,3′-bipyrrolidin-1′-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-{methyl[(3R)-pyrrolidin-3-yl]amino}-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(2-methyl-1-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(1-methylpiperidin-4-yl)oxy]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(3S)-pyrrolidin-3-yloxy]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(piperidin-4-yloxy)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(3,4-dimethoxyphenyl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-{methyl[(3R)-1-methylpyrrolidin-3-yl]amino}-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-(dimethylamino)pyrrolidin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-aminopiperidin-1-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-quinolizin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[(3aR,6aR)-1-methylhexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[1-(2-hydroxyethyl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-quinolizin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R,5S)-3,4,5-trimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-[(3aR,6aS)-5-methylhexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[4-(dimethylamino)piperidin-1-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(1R,5S)-8-azabicyclo[3.2.1]oct-2-en-3-yl]-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1,2,5,6-tetrahydropyridin-3-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3-(dimethylamino)pyrrolidin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-ethyl-1,3-benzoxazol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-ethyl-1,3-benzoxazol-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-[(3aR,6aS)-5-methylhexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-aminopiperidin-1-yl)-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3-(dimethylamino)pyrrolidin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-(dimethylamino)pyrrolidin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-aminopiperidin-1-yl)-7-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[(3S)-3-(dimethylamino)pyrrolidin-1-yl]-7-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[(3R)-3-(dimethylamino)pyrrolidin-1-yl]-7-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[(3aR,6aS)-5-(2-hydroxyethyl)hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[(3aS,6aS)-1-methylhexahydropyrrolo[3,4-b]pyrrol-5(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[(3aR,6aS)-5-(propan-2-yl)hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3-(dimethylamino)pyrrolidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3,3-dimethylpiperazin-1-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(piperidin-4-yloxy)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3-fluoro-4-methoxyphenyl)-2-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-(dimethylamino)piperidin-1-yl]-7-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[(4aR,7aR)-octahydro-6H-pyrrolo[3,4-b]pyridin-6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-ethylpiperazin-1-yl)-2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(4-propylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3aR,6aS)-5-ethylhexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-9-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-[(4aR,7aR)-1-methyloctahydro-6H-pyrrolo[3,4-b]pyridin-6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-9-methyl-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3-fluoro-4-methoxyphenyl)-2-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3-fluoro-4-methoxyphenyl)-2-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(1-propyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(1R,5S)-8-methyl-8-azabicyclo[3.2.1]oct-3-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(2R)-2-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-quinolizin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(4-methylpiperazin-1-yl)-4H-quinolizin-4-one 7-[(3S)-4-ethyl-3-methylpiperazin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-quinolizin-4-one 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-quinolizin-4-one 7-(4-aminopiperidin-1-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-quinolizin-4-one 2-(3-fluoro-4-methoxyphenyl)-9-methyl-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-9-methyl-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(cyclopropylamino)piperidin-1-yl]-2-(3,4-dimethoxyphenyl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3,4-dimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(3R)-3,4-dimethylpiperazin-1-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3,3-dimethylpiperazin-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-cyclopropylpiperazin-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-ethyl-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[4-(dimethylamino)piperidin-1-yl]-9-ethyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[1-(2-hydroxyethyl)-1,2,3,6-tetrahydropyridin-4-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(2-methyl-1,3-benzothiazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-aminopiperidin-1-yl)-2-(2-methyl-1,3-benzothiazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-2-(2-methyl-1,3-benzothiazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-propyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrimido[1,2-a]pyrimidin-4-one 7-(1-cyclopropyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclobutyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(oxetan-3-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-[4-(methylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[4-(ethylamino)piperidin-1-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-8-methyl-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[4-(propan-2-ylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclobutyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[1-(oxetan-3-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1-propyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[4-(methylamino)cyclohex-1-en-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[4-(dimethylamino)cyclohex-1-en-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-{4-[ethyl(methyl)amino]cyclohex-1-en-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-{4-[methyl(propyl)amino]cyclohex-1-en-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3,4-dimethoxyphenyl)-2-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[4-(propan-2-yl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[4-(propan-2-yl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3,4-dimethoxyphenyl)-2-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-(1-propyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclobutyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(3,4-dimethoxyphenyl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 7-(4-aminopiperidin-1-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3-aminopyrrolidin-1-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3-(dimethylamino)pyrrolidin-1-yl]-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[4-(2-methoxyethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-[1-(oxetan-3-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-8-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclopropyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(3,4-dimethoxyphenyl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-8-methyl-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)-1,2,3,6-tetrahydropyridin-4-yl]-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclopropyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-1,3-benzothiazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 7-[(1S,4S)-2,5-diazabicyclo[2.2.1]hept-2-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(1S,4S)-5-methyl-2,5-diazabicyclo[2.2.1]hept-2-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(1S,4S)-5-ethyl-2,5-diazabicyclo[2.2.1]hept-2-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[cis-4-(methylamino)cyclohexyl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-(piperidin-3-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-[4-(propylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-ethyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-cyclopropylpiperazin-1-yl)-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-ethyl-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-[4-(propan-2-ylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-ethyl-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-methyl-7-[4-(morpholin-4-yl)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:1) 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(pyrrolidin-1-yl)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4′-bipiperidin-1′-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(4-methylpiperazin-1-yl)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(morpholin-4-yl)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-{4-[(2-hydroxyethyl)amino]piperidin-1-yl}-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-ethyl-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(diethylamino)piperidin-1-yl]-2-(3,4-dimethoxyphenyl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-ethyl-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-[4-(pyrrolidin-1-yl)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-methylpiperazin-1-yl)-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[6-(dimethylamino)pyridin-3-yl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(diethylamino)piperidin-1-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-{4-[(2-hydroxyethyl)(methyl)amino]piperidin-1-yl}-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-ethyl-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[6-(dimethylamino)pyridin-3-yl]-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(diethylamino)piperidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-9-ethyl-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-{4-[(2-methoxyethyl)amino]piperidin-1-yl}-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(1-propyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[6-(dimethylamino)pyridin-3-yl]-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-ethylpiperazin-1-yl)-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(2-hydroxyethyl)piperazin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-propylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)-1,2,3,6-tetrahydropyridin-4-yl]-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3-methylpiperazin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclopropyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-methyl-1,4-diazepan-1-yl)-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-4-ethyl-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-ethyl-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-3-methyl-4-(propan-2-yl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methyl-4-(propan-2-yl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 7-(1-ethylpiperidin-4-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(1-methyl-1H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-ethylpiperazin-1-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-ethyl-3-methylpiperazin-1-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(octahydro-5H-pyrrolo[3,2-c]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 7-(1-ethylpiperidin-4-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrimido[1,2-b]pyridazin-4-one 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(2-hydroxyethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-(2-methoxyethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-{(3S)-4-[2-(2-hydroxyethoxy)ethyl]-3-methylpiperazin-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-cyclopropyl-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-cyclobutyl-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-(2-hydroxyethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-(2-methoxyethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-(2-hydroxyethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-{(3S)-4-[2-(2-hydroxyethoxy)ethyl]-3-methylpiperazin-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methyl-4-(propan-2-yl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-4-cyclopropyl-3-methylpiperazin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-4-cyclobutyl-3-methylpiperazin-1-yl]-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3,3-dimethylpiperazin-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(diethylamino)piperidin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-7-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-7-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-7-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-ethylpiperazin-1-yl)-2-(2-methylimidazo[1,2-a]pyridin-7-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-7-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-7-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[(3R,5S)-3,4,5-trimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-{4-[(dimethylamino)methyl]piperidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(pyrrolidin-1-ylmethyl)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(piperidin-1-ylmethyl)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-{4-[(dimethylamino)methyl]piperidin-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[4-(pyrrolidin-1-ylmethyl)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[4-(piperidin-1-ylmethyl)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)-1,2,3,6-tetrahydropyridin-4-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{4-[(2-hydroxyethyl)(methyl)amino]piperidin-1-yl}-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[4-(propylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-amino-4-methylpiperidin-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(4-ethylpiperazin-1-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-[4-(2-hydroxyethyl)piperazin-1-yl]-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(ethylamino)piperidin-1-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-{4-[bis(2-hydroxyethyl)amino]piperidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(oxetan-3-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methyloctahydro-5H-pyrrolo[3,2-c]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{4-[(2-hydroxyethyl)amino]piperidin-1-yl}-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[4-(methylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[4-(propan-2-ylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-propylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(propan-2-yl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-cyclopropylpiperazin-1-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-cyclobutylpiperazin-1-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(oxetan-3-yl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethyloctahydro-5H-pyrrolo[3,2-c]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)octahydro-5H-pyrrolo[3,2-c]pyridin-5-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methoxy-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-hydroxy-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-cyclobutylpiperidin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-4-ethyl-3-methylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-3-methyl-4-propylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(2-hydroxyethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(pyrrolidin-1-yl)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclopropylpiperidin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclobutylpiperidin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-3-methyl-4-(propan-2-yl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-4-cyclopropyl-3-methylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-4-cyclobutyl-3-methylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-3-methyl-4-(oxetan-3-yl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-cyclobutylpiperazin-1-yl)-2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-4-(2-hydroxyethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-4-cyclobutyl-3-methylpiperazin-1-yl]-2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-4-(2-hydroxyethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-4-cyclobutyl-3-methylpiperazin-1-yl]-2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-propylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-fluoroethyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(3-fluoropropyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(2-fluoroethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(3-fluoropropyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(2-fluoroethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(3-fluoropropyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-fluoroethyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(3-fluoropropyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{(3R)-4-[2-(2-hydroxyethoxy)ethyl]-3-methylpiperazin-1-yl}-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(2-hydroxyethyl)-3-methylpiperazin-1-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-[8-(hydroxymethyl)-2-methylimidazo[1,2-a]pyridin-6-yl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[8-(hydroxymethyl)-2-methylimidazo[1,2-a]pyridin-6-yl]-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-ethylpiperazin-1-yl)-2-[8-(hydroxymethyl)-2-methylimidazo[1,2-a]pyridin-6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclopropylpiperidin-4-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclobutylpiperidin-4-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(oxetan-3-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-cyclopropyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-cyclopropyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-cyclopropyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-cyclopropyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-propylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-(dimethylamino)-6-methylpyrazolo[1,5-a]pyrazin-2-yl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1H-benzimidazol-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-ethylpiperazin-1-yl)-2-(2-methyl-1H-benzimidazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one 7-[1-(2,2-dimethyl-1,3-dioxan-5-yl)piperidin-4-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(1,3-dihydroxypropan-2-yl)piperidin-4-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-4-ethyl-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclobutylpiperidin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)-4-methylpiperidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(ethylamino)-4-methylpiperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-methyl-4-(propylamino)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{4-[(2-hydroxyethyl)amino]-4-methylpiperidin-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclobutylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1-propylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-cyclopropyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-cyclopropyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-cyclopropyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-cyclopropyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclopropylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(1-methylpiperidin-4-yl)oxy]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-methylpiperazin-1-yl)-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-ethylpiperazin-1-yl)-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(2-hydroxyethyl)piperazin-1-yl]-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3-methylpiperazin-1-yl]-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-[(3R)-3-methyl-4-(propan-2-yl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-amino-4-methylpiperidin-1-yl)-2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3S)-3-ethylpiperazin-1-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3-methylpiperazin-1-yl]-2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-amino-4-methylpiperidin-1-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3-aminoprop-1-yn-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(3-aminopropyl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(1-ethyl-3-methylpyrrolo[1,2-a]pyrazin-7-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(1-ethyl-3-methylpyrrolo[1,2-a]pyrazin-7-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-[(3S)-3,4-dimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[3-(dimethylamino)azetidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[3-(diethylamino)azetidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[3-(pyrrolidin-1-yl)azetidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3aR,6aS)-hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl]-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-(aminomethyl)pyrrolidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[3-(piperidin-1-yl)azetidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(2,7-diazaspiro[4.4]non-2-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[3-(dimethylamino)propyl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-{(3S)-3-[(dimethylamino)methyl]pyrrolidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(1-methyl-1H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-{(3S)-3-[(diethylamino)methyl]pyrrolidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{(3S)-3-[(ethylamino)methyl]pyrrolidin-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 7-{3-[(dimethylamino)methyl]azetidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-{3-[(diethylamino)methyl]azetidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-ethyl-3-methylpyrrolo[1,2-a]pyrazin-7-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(1-methyl-1H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3,4-dimethylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-9-methyl-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-cyclobutylpiperidin-4-yl)-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-[(3R)-3-(aminomethyl)pyrrolidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(2S,6S)-2,6-dimethyl-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-{(3R)-3-[(dimethylamino)methyl]pyrrolidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(2S,6S)-2,6-dimethylpiperidin-4-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methylimidazo[1,2-a]pyridin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2′-methyl-7-(piperazin-1-yl)-4H,4′H-2,7′-bipyrido[1,2-a]pyrimidine-4,4′-dione 2-[4-(difluoromethoxy)-3-fluorophenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-fluoro-6-hydroxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-hydroxy-2-methylquinazolin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[6-(dimethylamino)pyridin-3-yl]-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-[4-(dimethylamino)-6-methylpyrazolo[1,5-a]pyrazin-2-yl]-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[3-(trifluoromethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one tert-butyl 4-[2-(4-hydroxy-2-methoxyphenyl)-4-oxo-4H-pyrido[1,2-a]pyrimidin-7-yl]-3,6-dihydropyridine-1(2H)-carboxylate tert-butyl 4-[2-(2-methoxy-4-{[(trifluoromethyl)sulfonyl]oxy}phenyl)-4-oxo-4H-pyrido[1,2-a]pyrimidin-7-yl]-3,6-dihydropyridine-1(2H)-carboxylate 2-[4-(2-hydroxypyridin-4-yl)-2-methoxyphenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[2-hydroxy-4-(2-hydroxypyridin-4-yl)phenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-[1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-(1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(2,2,6,6-tetramethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(2,2,6,6-tetramethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(7-fluoro-2-methyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(7-fluoro-2-methyl-2H-indazol-5-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one, and 7-(1-ethylpiperidin-4-yl)-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one wherein the form of the compound is selected from the group consisting of a salt, prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.
 7. A compound selected from the group consisting of: 2-(6-methylimidazo[1,2-a]pyridin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2′-methyl-7-(piperazin-1-yl)-4H,4′H-2,7′-bipyrido[1,2-a]pyrimidine-4,4′-dione 2-[4-(difluoromethoxy)-3-fluorophenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-fluoro-6-hydroxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-hydroxy-2-methylquinazolin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[6-(dimethylamino)pyridin-3-yl]-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-[4-(dimethylamino)-6-methylpyrazolo[1,5-a]pyrazin-2-yl]-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[3-(trifluoromethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one tert-butyl 4-[2-(4-hydroxy-2-methoxyphenyl)-4-oxo-4H-pyrido[1,2-a]pyrimidin-7-yl]-3,6-dihydropyridine-1(2H)-carboxylate tert-butyl 4-[2-(2-methoxy-4-{[(trifluoromethyl)sulfonyl]oxy}phenyl)-4-oxo-4H-pyrido[1,2-a]pyrimidin-7-yl]-3,6-dihydropyridine-1(2H)-carboxylate 2-[4-(2-hydroxypyridin-4-yl)-2-methoxyphenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[2-hydroxy-4-(2-hydroxypyridin-4-yl)phenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-[1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-(1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(2,2,6,6-tetramethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(2,2,6,6-tetramethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(7-fluoro-2-methyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(7-fluoro-2-methyl-2H-indazol-5-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one, and 7-(1-ethylpiperidin-4-yl)-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one wherein the form of the compound is selected from the group consisting of a salt, prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.
 8. The method of claim 6, wherein the compound is a compound salt selected from the group consisting of: 2-(3,5-difluoro-4-hydroxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:1) 7-[4-(dimethylamino)piperidin-1-yl]-2-(3-fluoro-4-methoxyphenyl)-4H-quinolizin-4-one acetate (1:1) 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(piperidin-4-yl)-4H-pyrimido[1,2-b]pyridazin-4-one trifluoroacetate (1:1) 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-[4-(2-hydroxypyridin-4-yl)-2-methoxyphenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:1) 2-[2-hydroxy-4-(2-hydroxypyridin-4-yl)phenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one trifluoroacetate (1:1) 7-(piperazin-1-yl)-2-(1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:1) 7-[(3S)-3-methylpiperazin-1-yl]-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(1,7-dimethyl-1H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(1,7-dimethyl-1H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(2,7-dimethyl-2H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(2,7-dimethyl-2H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:1) 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:1), and 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:2) wherein the form of the compound salt is selected from the group consisting of a prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.
 9. The compound of claim 7, wherein the compound is a compound salt selected from the group consisting of: 2-[4-(2-hydroxypyridin-4-yl)-2-methoxyphenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:1) 2-[2-hydroxy-4-(2-hydroxypyridin-4-yl)phenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one trifluoroacetate (1:1) 7-(piperazin-1-yl)-2-(1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:1) 7-[(3S)-3-methylpiperazin-1-yl]-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(1,7-dimethyl-1H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(1,7-dimethyl-1H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(2,7-dimethyl-2H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(2,7-dimethyl-2H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one hydrochloride (1:2) 9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:2) 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:1) 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:1), and 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:2) wherein the form of the compound salt is selected from the group consisting of a prodrug, hydrate, solvate, clathrate, isotopologue, racemate, enantiomer, diastereomer, stereoisomer, polymorph and tautomer form thereof.
 10. The method of claim 1, wherein the effective amount of the compound or form thereof is in a range of from about 0.001 mg/kg/day to about 500 mg/kg/day.
 11. The method of claim 8, wherein the effective amount of the compound or form thereof is in a range of from about 0.001 mg/kg/day to about 500 mg/kg/day.
 12. The method of claim 1, wherein a pharmaceutical composition comprises the compound or form thereof in admixture with one or more pharmaceutically acceptable excipients.
 13. The method of claim 6, wherein a pharmaceutical composition comprises the compound or form thereof in admixture with one or more pharmaceutically acceptable excipients.
 14. The method of claim 8, wherein a pharmaceutical composition comprises the compound or form thereof in admixture with one or more pharmaceutically acceptable excipients.
 15. A pharmaceutical composition comprising the compound or form thereof of claim 7 in admixture with one or more pharmaceutically acceptable excipients.
 16. A pharmaceutical composition comprising the compound or form thereof of claim 9 in admixture with one or more pharmaceutically acceptable excipients.
 17. The method of claim 6, wherein the compound or form thereof is selected from the group consisting of: 2-(6-methylimidazo[1,2-a]pyridin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3-fluoro-4-methoxyphenyl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methylimidazo[1,2-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methylimidazo[1,2-a]pyrazin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methoxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-chloropyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-chloro-6-methoxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(imidazo[1,2-a]pyridin-7-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(imidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6,8-dimethylimidazo[1,2-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-[2-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-ethylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,3-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-(1H-pyrrolo[2,3-b]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-pyrrolo[2,3-b]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-(4-methyl-1,3-thiazol-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methyl-1,3-thiazol-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-methyl-1H-imidazol-1-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-(1-methyl-1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-pyrazol-4-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,5-dimethoxypyridin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzothiazol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-(pyridin-3-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-methoxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3,4-dimethylpiperazin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R,5S)-3,4,5-trimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(3,4-dimethoxyphenyl)-7-[4-(dimethylamino)piperidin-1-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-ethylpiperazin-1-yl)-2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(4-fluoro-2-methyl-1,3-benzoxazol-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(8aS)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(8aR)-hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclobutyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(1S,4S)-5-methyl-2,5-diazabicyclo[2.2.1]hept-2-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(1S,4S)-5-ethyl-2,5-diazabicyclo[2.2.1]hept-2-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-cyclopropylpiperazin-1-yl)-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one hydrochloride (1:1) 2-(2-methyl-1,3-benzoxazol-6-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-1,3-benzoxazol-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(morpholin-4-yl)piperidin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[6-(dimethylamino)pyridin-3-yl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[6-(dimethylamino)pyridin-3-yl]-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(diethylamino)piperidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-2-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[6-(dimethylamino)pyridin-3-yl]-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-[1-(propan-2-yl)-1,2,3,6-tetrahydropyridin-4-yl]-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5,7-dimethylfuro[2,3-c]pyridin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(1-methyl-1H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(2-hydroxyethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-{(3S)-4-[2-(2-hydroxyethoxy)ethyl]-3-methylpiperazin-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(2-hydroxyethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)piperidin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(1-methyl-1H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1-methyl-1H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-7-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-7-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-7-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{4-[(2-hydroxyethyl)(methyl)amino]piperidin-1-yl}-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-(4-amino-4-methylpiperidin-1-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(4-ethylpiperazin-1-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-[4-(2-hydroxyethyl)piperazin-1-yl]-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(8-chloro-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methyl-2H-indazol-5-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{4-[(2-hydroxyethyl)amino]piperidin-1-yl}-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)octahydro-5H-pyrrolo[3,2-c]pyridin-5-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylimidazo[1,2-a]pyridin-6-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-cyclobutylpiperidin-4-yl)-2-(2-methylimidazo[1,2-a]pyridin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(2-hydroxyethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methyl-1,4-diazepan-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclopropylpiperidin-4-yl)-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-[(3R)-4-(2-hydroxyethyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-fluoroethyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[4-(3-fluoropropyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(3-fluoropropyl)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-fluoroethyl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[(3R)-4-(2-hydroxyethyl)-3-methylpiperazin-1-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 2-[8-(hydroxymethyl)-2-methylimidazo[1,2-a]pyridin-6-yl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[8-(hydroxymethyl)-2-methylimidazo[1,2-a]pyridin-6-yl]-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(propan-2-yl)piperidin-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-cyclopropyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-cyclopropyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-cyclopropyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[4-(dimethylamino)-6-methylpyrazolo[1,5-a]pyrazin-2-yl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-ethyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[4-(dimethylamino)-4-methylpiperidin-1-yl]-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-{4-[(2-hydroxyethyl)amino]-4-methylpiperidin-1-yl}-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclobutylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[1-(2-hydroxyethyl)piperidin-4-yl]-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(8-cyclopropyl-2-methylimidazo[1,2-a]pyridin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-cyclopropylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3-methylpiperazin-1-yl]-2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R)-3-methylpiperazin-1-yl]-2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-[2-methyl-8-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3R,5S)-3,5-dimethylpiperazin-1-yl]-2-(1-ethyl-3-methylpyrrolo[1,2-a]pyrazin-7-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1,4-diazepan-1-yl)-2-(1-ethyl-3-methylpyrrolo[1,2-a]pyrazin-7-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-[(3S)-3,4-dimethylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-[(3R)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(6-methyl-4-propylpyrazolo[1,5-a]pyrazin-2-yl)-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-{(3S)-3-[(dimethylamino)methyl]pyrrolidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-indazol-5-yl)-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-{3-[(dimethylamino)methyl]azetidin-1-yl}-2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[(3S)-3-methylpiperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(6-methylimidazo[1,2-a]pyridin-2-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2′-methyl-7-(piperazin-1-yl)-4H,4′H-2,7′-bipyrido[1,2-a]pyrimidine-4,4′-dione 2-[4-(difluoromethoxy)-3-fluorophenyl]-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(5-fluoro-6-hydroxypyridin-3-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-hydroxy-2-methylquinazolin-6-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[6-(dimethylamino)pyridin-3-yl]-7-(1-methylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-[4-(dimethylamino)-6-methylpyrazolo[1,5-a]pyrazin-2-yl]-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[3-(trifluoromethyl)piperazin-1-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(4-ethylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-indazol-5-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one tert-butyl 4-[2-(4-hydroxy-2-methoxyphenyl)-4-oxo-4H-pyrido[1,2-a]pyrimidin-7-yl]-3,6-dihydropyridine-1(2H)-carboxylate tert-butyl 4-[2-(2-methoxy-4-{[(trifluoromethyl)sulfonyl]oxy}phenyl)-4-oxo-4H-pyrido[1,2-a]pyrimidin-7-yl]-3,6-dihydropyridine-1(2H)-carboxylate 2-[4-(2-hydroxypyridin-4-yl)-2-methoxyphenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-[2-hydroxy-4-(2-hydroxypyridin-4-yl)phenyl]-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4-ethyl-6-methylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-9-methyl-7-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-[methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-[1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl]-4H-pyrido[1,2-a]pyrimidin-4-one 7-(piperazin-1-yl)-2-(1H-pyrazol-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-[(3S)-3-methylpiperazin-1-yl]-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2-methylpyrazolo[1,5-a]pyridin-5-yl)-7-(piperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(1,7-dimethyl-1H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-pyrazolo[3,4-c]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-pyrazolo[4,3-b]pyridin-5-yl)-7-(1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methyl-2H-indazol-5-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(2,2,6,6-tetramethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methyl-2H-indazol-5-yl)-7-(2,2,6,6-tetramethylpiperidin-4-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(2,8-dimethylimidazo[1,2-a]pyridin-6-yl)-7-(4-methylpiperazin-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one 2-(7-fluoro-2-methyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-2-(7-fluoro-2-methyl-2H-indazol-5-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one 7-(1-ethylpiperidin-4-yl)-9-methyl-2-(2-methylimidazo[1,2-b]pyridazin-6-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(2,7-dimethyl-2H-indazol-5-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-7-(piperidin-4-yl)-4H-pyrazino[1,2-a]pyrimidin-4-one 2-(1,3-dimethylpyrrolo[1,2-a]pyrazin-7-yl)-7-(1-ethylpiperidin-4-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one, and 7-(1-ethylpiperidin-4-yl)-2-(8-fluoro-2-methylimidazo[1,2-a]pyridin-6-yl)-9-methyl-4H-pyrazino[1,2-a]pyrimidin-4-one.
 18. The method of claim 17, wherein a pharmaceutical composition comprises the compound or form thereof in admixture with one or more pharmaceutically acceptable excipients.
 19. The method of claim 6, wherein the compound or form thereof is not 2-(4,6-dimethylpyrazolo[1,5-a]pyrazin-2-yl)-7-[1-(2-hydroxyethyl)piperidin-4-yl]-9-methyl-4H-pyrido[1,2-a]pyrimidin-4-one.
 20. The method of claim 19, wherein a pharmaceutical composition comprises the compound or form thereof in admixture with one or more pharmaceutically acceptable excipients. 